Expandable last for furnishing footwear with an insert and method for furnishing footwear with an insert

ABSTRACT

An expandable last ( 2 ) for furnishing footwear ( 110 ) with an insert ( 100 ) includes an expansion assembly ( 40 ); an expandable shell ( 6 ), arranged around the expansion assembly ( 40 ); and a liquid chamber ( 8 ) within the expandable shell ( 6 ); wherein the expandable last ( 2 ) is insertable into the footwear ( 110 ) through a collar of the footwear ( 110 ) and wherein the expandable shell ( 6 ) is configured to expand for pressing the insert ( 100 ) towards an inside of the footwear ( 110 ); and wherein the expansion assembly ( 40 ) is configured to adapt its extension for exerting localized pressure onto the expandable shell ( 6 ) towards the inside of the footwear ( 110 ).

The present invention is in the field of producing footwear. Inparticular, the present invention is in the field of equipping footwearwith an insert.

In recent years, there has been a trend towards waterproof shoes.Waterproof and breathable shoes have been developed that provide for anall-around waterproof structure around the wearer's foot, but at thesame time provide breathability, such that moisture and sweat from thewearer's foot can escape from the interior of the shoe. While suchwaterproof and breathable shoes provide a very convenient feel for theuser in a wide range of usage scenarios, the percentage of waterprooffootwear among all shoes is still relatively low.

Accordingly, it would be beneficial to provide equipment that allows forwaterproofing footwear, while maintaining a high degree of flexibilityin the footwear production process. It would further be beneficial toprovide a method that allows for waterproofing footwear, whilemaintaining a high degree of flexibility in the footwear productionprocess.

Exemplary embodiments of the invention include an expandable last forfurnishing footwear with an insert, comprising: a form-stable coresupport element; an expandable shell, arranged around the core supportelement; a liquid chamber within the expandable shell; and a liquidport, providing liquid communication between the liquid chamber and anexternal liquid source; wherein the expandable last is insertable intothe footwear through a collar of the footwear and wherein, whenreceiving liquid in the liquid chamber via the liquid port, theexpandable shell is configured to expand for pressing the insert towardsan inside of the footwear.

Exemplary embodiments of the invention allow for equipping footwear withan insert in a flexible and efficient manner. In particular, exemplaryembodiments of the invention allow for equipping footwear with an inserton the inside thereof, when the collar is the only access point to theinterior of the footwear. Further in particular, exemplary embodimentsof the invention allow for equipping footwear with an insert, when thefootwear is otherwise already completely assembled or close to beingcompletely assembled. Footwear may be equipped with a waterproof,breathable insert, such as a waterproof, breathable bootie, and may thusbe made waterproof in a convenient, flexible, and efficient manner. Inparticular, when the footwear has been designed and assembled inaccordance with a conventional non-waterproof design and is ready to beworn or close to being ready to be worn, it can still be equipped with awaterproof, breathable insert. In the case of footwear that is ready tobe worn, it may also be said that readily assembled non-waterprooffootwear may be retrofitted with a waterproof, breathable insert andmay, thus, be made waterproof.

According to exemplary embodiments of the invention, the expandable lastis insertable into the footwear through a collar of the footwear, andthe expandable shell is configured to expand, when receiving liquid inthe liquid chamber via the liquid port, for pressing the insert towardsan inside of the footwear. The expandable last may be convenientlyintroduced into the interior of the footwear, and the expandable shellmay exert pressure onto the insert with a high degree of uniformity.With the expandable shell expanding upon receiving liquid in the liquidchamber via the liquid port and engaging with the insert, thepressure-balancing effect, inherent to liquids, may be taken advantageof in very close proximity to the insert. With the expandable shellforming the barrier between the liquid chamber, in which the pressure isbuilt up, and the insert, a highly direct and highly uniform pressuremay be exerted onto the insert for pressing the insert towards theinside of the footwear. The expandable shell is configured to expandand, thus, to press the insert towards the inside of the footwear duringoperation of the expandable last. It is understood that the expandablelast is configured to receive liquid in the liquid chamber in operationand that the expandable shell is configured to exert the pressure on theinsert in operation, when arranged in the footwear.

According to exemplary embodiments of the invention, the expandable lastis configured for furnishing footwear with an insert. In particular, theexpandable last may be configured for any one or any subset or all ofinserting an insert into the interior of the footwear, positioning aninsert in the interior of the footwear, mechanically engaging an insertwith the inside of the footwear, and attaching/adhering an insert to theinside of the footwear. The expandable last is configured to exertpressure onto an insert against the inside of the footwear via theexpandable shell.

The expandable last has a form-stable core support element. The termform-stable core support element relates to a core support element thathas a substantially stable shape. In particular, it relates to a coresupport element that has no active shape adjusting means, such as aspring-loaded actuator, a hydraulic or pneumatic actuator, etc. The termform-stable does not exclude the core support element to have someelasticity and/or allow for some plastic deformation. For example, thecore support element may elastically and/or plastically deform, whilebeing pushed into the interior of the footwear. However, by beingform-stable, the core support element maintains its general shape. Theshape of the core support element may not undergo a substantialtransformation and may maintain its general appearance.

The expandable last has an expandable shell, arranged around the coresupport element. The expandable shell may be made of any material thatexpands under the pressure of the liquid in the liquid chamber. Theexpansion of the expandable shell may comprise an elastic deformationand/or a plastic deformation. The expandable shell may be a kind ofballoon/bladder that expands upon receiving liquid in the liquidchamber. In particular, the expandable shell may be a balloon around theform-stable core support elements, with the liquid chamber being formedon the inside of the balloon. The expandable shell may be expandable atportions thereof or may be expandable substantially everywhere. In otherwords, the expandable nature of the shell may be provided in portionsthereof or across the whole component. The expandable shell may thus beconfigured to press the insert towards the inside of the footwear atselected portions of the insert or substantially everywhere along theinsert. The expandable shell may be substantially foot-shaped. Thefoot-shaped nature of the expandable shell may be present in theun-expanded state. It is also possible that the expandable shell assumesa kind of foot shape, when receiving liquid in the liquid chamber.

The expandable last comprises a form-stable core support element and anexpandable shell, arranged around the core support element. In this way,the stability/re-enforcing strength of the core support element iscombined with the expandable properties of the expandable shell. In thisway, a good compromise between insertability of the expandable last andadaptability to the inside contour of the footwear may be achieved.

The expandable last is insertable into the footwear through a collarthereof. In other words, the expandable last is insertable into thefootwear through a foot insertion opening of the footwear. In yet otherwords, the expandable last is insertable into the footwear from the top,when placing the footwear on a table or other horizontal structure inits normal use orientation.

The expandable last comprises a liquid chamber within the expandableshell. The expandable shell may be liquid-tight/liquid proof, inparticular water-tight/waterproof. With liquid, in particular water,being used in the liquid chamber in operation, the insert can be pressedtowards the insert of the footwear in a particularly efficient manner.As compared to using gas for exerting the pressure, a lower amount offluid may needed and the need for a high gas pressure may be eliminated.For example, in particular applications, a water pressure of about 0.2bar may be suitable for pressing an insert towards the inside of thefootwear, while air pressures of 6-7 bar would be required for achievingcomparable results. Many expandable materials cannot handle such highpressures and would burst/tear, such that the using of liquids providesa much higher degree of design flexibility than using gases forexpanding the expandable shell. Also, liquids have beneficialproperties, when counter pressure from the outside of the footwear isapplied. For example, when applying counter-pressure in a pressurechamber, as described below, the non-compressibility of the liquidallows for using comparably low liquid pressures. As compared thereto,the compressed air within the expandable shell would have to have a muchhigher pressure, in order to avoid compression due to the counterpressure.

The expandable last has a liquid port, providing liquid communicationbetween the liquid chamber and an external liquid source. A liquid-tightseal may be provided between the liquid chamber and the liquid port. Theliquid port may have a connection piece for attaching a liquid linetowards the external liquid source. This connection piece may be anysuitable male or female, threaded or unthreaded connection piece. It mayhave a suitable locking mechanism for ensuring a safe connection betweenthe liquid port and the external liquid source/the liquid line. Theterminology of the liquid port providing liquid communication betweenthe liquid chamber and an external liquid source means that the liquidport has the capacity to pass liquid therethrough and to allow forliquid communication between the liquid chamber and the external liquidsource in operation.

With the expandable last having an expandable shell, the expandable lastmay be used over a range of shoe sizes. In particular, it is possiblethat the expandable last is suitable for being used for a range of up to2 or 3 or 4 or 5 or 6 or 7 or 8 shoe sizes (European shoe sizes). It maythus be possible to cover the whole range of standard adult shoe sizes,i.e. European shoe sizes 35 to 47, with two or three differentexpandable lasts only. Further, the expandable last may be used for avariety of different shoe styles, with the expandable shell adapting tothe inner contour of the footwear via the liquid in the liquid chamber.

According to a further embodiment, the core support element issubstantially L-shaped or substantially T-shaped or substantiallyU-shaped or substantially foot-shaped. In this way, the core supportelement may be particularly suitable for providing a high degree ofstability to the expandable last. The core support element may bedimensioned to extend over at least 50%, in particular over at least70%, further in particular over between 90% and 100% of the verticalextension of the interior of the footwear and/or over at least 30%, inparticular over at least 50%, further in particular over at least 70%,or even over between 90% and 100% of the horizontal extension of theinterior of the footwear.

According to a further embodiment, the core support element is rigid. Inparticular, the core support element may be made of metal or made of arigid plastic material or made of sintered material. The core supportelement may be considered rigid in case it does not undergo adeformation during manual introduction of the expandable last into thefootwear. The rigid core support element may provide a high degree ofstability to the expandable last during use in the footwear.

According to a further embodiment, the core support element is flexible.In particular, the core support element may be resilient, further inparticular made from resilient rubber material. The core support elementmay be considered flexible in case its shape changes temporarily orpermanently during manual introduction of the expandable last into thefootwear. A flexible core support element may be particularly suitablefor an easy introduction of the expandable last into the interior of thefootwear. A resilient core support element may provide a good compromisebetween easy insertability and a high degree of stability, when insertedinto the footwear. The core support element may be made from anysuitable flexible material. Suitable flexible materials include rubber,polyurethane, silicone, and thermoplastic polyurethane materials. Theselection of a rigid material or a flexible material for the coresupport element may be made dependent on the dimensions of the coresupport element. In case the dimensions of the core support element areclose to the dimensions of the interior of the footwear, a flexiblematerial may allow for a much easier insertability through the collar ofthe footwear. In case the dimensions of the core support element aresubstantially smaller than the dimensions of the interior of thefootwear, insertability may be less of an issue and a rigid material maybe selected.

According to a further embodiment, the liquid chamber comprisessubstantially the entire volume between the core support element and theexpandable shell. In this way, the expandable last is highly flexible,having a large liquid volume in the liquid chamber during operation. Theliquid chamber covering such a large volume may also allow theexpandable last to have an overall low number of components. In aparticular embodiment, the expandable last may be free of additionalcomponents between the form-stable core support element and theexpandable shell, with the volume between the form-stable core supportelement and the expandable shell forming the liquid chamber. However, itis also possible that additional components are provided between thecore support element and the expandable shell. For example, fillerelements, such as filler balls or cuboid filler elements, may beprovided between the core support element and the expandable shell. Suchfiller elements may be free-floating between the core support elementand the expandable shell and/or may be attached to the core supportelement and/or the expandable shell. The filler elements may reduce theliquid volume needed for generating a desired pressure on the insert bythe expandable shell. In this way, the furnishing of the footwear withthe insert may be achieved in a particularly short time frame.

According to a further embodiment, the core support element comprises atleast one liquid supply line, coupled to the liquid port and providingliquid communication between the liquid port and the liquid chamber. Theliquid may reach the liquid chamber at one or more desired locations viathe at least one liquid supply line. The entirety of the liquid supplylines may also be referred to as liquid supply line system. The at leastone liquid supply line may have one or more openings towards the liquidchamber. An efficient distribution of the liquid in the liquid chambermay be achieved, and a beneficial dynamic build-up of the pressurewithin the expandable shell may be made possible via a suitable designof the liquid supply line system and the opening(s).

According to a further embodiment, the at least one liquid supply lineis arranged within the core support element and has at least one openingtowards the liquid chamber. The core support element may serve thedouble purpose of providing stability to the expandable last and helpingthe liquid distribution in the liquid chamber by housing the at leastone liquid supply line.

According to a further embodiment, the expandable shell is elastic. Inparticular, the expandable shell may be made from any kind of elasticmaterial that is suitable for expanding under liquid pressure and forapplying pressure to the insert. The expandable shell may be made fromlatex material. In particular, the expandable shell may be made fromnatural latex material or synthetic latex material. It is also possiblethat the expandable shell is made from another kind of rubber material.Rubber materials, in particular latex materials, may provide for a goodcompromise between expandability and robustness with respect to changingpressures. Other suitable elastic materials are stretchable membranematerials and multilayer constructions. The expandable shell may be madefrom a liquid proof, in particular waterproof, material.

According to a further embodiment, the expandable shell is a one-layerstructure or a two-layer structure or a three-layer structure. It isalso possible for the expandable shell to have a higher number oflayers. With the expandable shell having a two-layer or three-layerdesign, a good compromise between expandability and tear-resistance maybe achieved. The two/three layers may be co-extensive. It is alsopossible that re-enforcing patches may be provided in critical portionsof the expandable shell, thus forming a multi-layer structure atselected portions. The two/three layers may be made from the samematerial or may be adapted to the particular requirements on theinside/outside of the expandable shell. For example, an inner layer maybe adapted to cooperate well with the liquid in the liquid chamber,while an outer layer may be adapted to cooperate well with the insert.One or more or all of the layers may be made from a liquid proof, inparticular waterproof, material.

According to a further embodiment, the expandable shell has, at least inone or more regions thereof, dimension-specific elastic properties. Inother words, the expandable shell may stretch in a particular dimensioneasier/quicker/at lower pressures than in one or more other dimensions.In this way, the expansion of the expandable shell may be controlled fora particular application/for a particular footwear. Further inparticular, the resulting shape of the expandable shell and/or thedynamic application of pressure onto different portions of the insertmay be controlled via the dimension-specific set-up of the expandableshell.

According to a further embodiment, the liquid chamber is at least partlyfilled with an open-cell foam. In particular, the majority of the liquidchamber or substantially the entire liquid chamber may be filled with anopen-cell foam. The open-cell foam may allow the liquid to distributewithin the liquid chamber, while giving the liquid chamber some inherentshape. In this way, the expandable last may be inherently shaped similarto the interior of the footwear, while still allowing the liquid toadapt the expandable shell to the inner contour of the footwear. Theopen-cell foam may be any suitable open-cell form. Suitable open-cellfoams include open-cell polyurethane foam, silicone foam, natural foam,and polyethylene foam. The open-cell foam itself may expand uponabsorbing liquid. However, it is also possible that the open-cell foamsubstantially maintains its shape upon absorbing liquid. As analternative/additionally, the liquid chamber may be at least partlyfilled with a spacer fabric. The spacer fabric may similarly providesome inherent shape to the expandable shell, while allowing the liquidto distribute and “fine-tune” the shape of the expandable shell, whenexpanding and engaging with the insert. Both the open-cell foam and thespacer fabric have no active shape adjusting means. They have aninherent shape, which may adapt passively to liquid entering theopen-call foam/spacer fabric.

According to a further embodiment, the expandable last further comprisesat least one expandable liquid bag, arranged outside or inside of theexpandable shell. In particular, the expandable last may comprise atleast one expandable liquid bag, arranged outside of the expandableshell, and/or may comprise at least one expandable liquid bag, arrangedinside of the expandable shell. In this way, a localized adaption of thepressure exerted onto the insert towards the inside of the footwear maybe achieved. In particular, the at least one expandable liquid bag maybe filled with liquid in such a manner that a different pressure levelis reached at the position of the at least expandable liquid bag, ascompared to the liquid chamber within the expandable shell. The at leastone expandable liquid bag may be used in a number of ways. For example,a higher liquid pressure may be used for pressing the insert harderagainst the inside of the footwear in positions where an attachmentbetween the insert and the footwear is difficult. A lower pressure inthe at least one expandable liquid bag may be used for reducing thestress on sensitive portions of the inside of the footwear. The at leastone expandable liquid bag may be smaller in volume than the liquidchamber, in particular less than 20%, further in particular less than10%, in volume of the liquid chamber. In this way, the liquid in the atleast one expandable liquid bag may be more locally constrained than theliquid in the liquid chamber. The liquid in the at least one expandableliquid bag may be prevented from flowing to portions of the footwearwhere the footwear yields most easily. The expandable liquid bag may beseen as an additional bladder/balloon, in particular an additionalbladder/balloon provided on the outside/inside of the expandable shell.

According to a further embodiment, the expandable last further comprisesat least one ancillary liquid port, providing liquid communicationbetween the at least one expandable liquid bag and at least one externalliquid source. Said at least one external liquid source may be one ormore separate liquid sources or may be/contain the same external liquidsource, as used for the liquid chamber within the expandable shell. Withthe at least one ancillary liquid port and the one or more separateexternal liquid sources, if present, the at least one expandable liquidbag may be used for flexibly controlling the pressure therein, ascompared to the pressure within the liquid chamber within the expandableshell.

According to a further embodiment, the expandable last further comprisesat least one ancillary liquid supply line, coupling the at least oneexpandable liquid bag to the at least one ancillary liquid port. In thisway, the at least one expandable liquid bag may perform its desiredfunction with a low liquid bag volume, with the ancillary liquid supplyline(s) achieving the liquid transfer between the ancillary liquidport(s) and the expandable liquid bag(s). The at least one expandableliquid supply line may run through the liquid chamber within theexpandable shell. However, it is also possible that the at least oneancillary liquid supply line runs along the outside of the expandableshell.

According to a further embodiment, the at least one expandable liquidbag comprises: an expandable liquid bag at an instep portion of theexpandable shell; an expandable liquid bag at a toe portion of theexpandable shell; an expandable liquid bag in a forefoot portion of theexpandable shell; an expandable liquid bag in an upper midfoot portionof the expandable shell. The expandable liquid bag at an instep portionof the expandable shell may be arranged on an outside or on an inside ofthe expandable shell. The expandable liquid bag at a toe portion of theexpandable shell may be arranged on an outside or on an inside of theexpandable shell. The expandable liquid bag in a forefoot portion of theexpandable shell may be arranged in the forefoot portion of theexpandable shell in such a manner that it abuts the expandable shellupon expansion. The expandable liquid bag in the upper midfoot portionof the expandable shell may be arranged in the midfoot portion in such amanner that it abuts the expandable shell upon expansion. With theexpandable liquid bag at an instep portion of the expandable shelland/or with the expandable liquid bag in an upper midfoot portion of theexpandable shell, the insert may be effectively pressed against theinside of the footwear at a tongue portion thereof. An attachmentbetween the insert and the tongue portion of the footwear, which may bedifficult due to the particular nature of tongue constructions, may beachieved in an effective manner. With the expandable liquid bag at a toeportion of the expandable shell and/or with the expandable liquid bag ina forefoot portion of the expandable shell, the insert may beeffectively pressed against the footwear at a toe portion thereof. Anattachment between the insert and the toe portion of the footwear, whichmay be difficult due to the irregularities of the inner contour in thetoe portion and/or due to the comparably stiff nature the toe portion ofthe footwear, which may act to push the liquid to other portions of theexpandable shell, may be achieved in an effective manner.

According to a further embodiment, the at least one expandable liquidbag is at least partly filled with an open-cell foam, in particular withan open-cell polyurethane foam, and/or with a spacer fabric. When filledwith liquid, the at least one expandable liquid bag may have a largerextension than the open-cell foam/the spacer fabric. The spacer fabricmay be particularly suitable for an expandable liquid bag that has asomewhat flat shape, such as an expandable liquid bag arranged at aninstep portion of the expandable shell.

According to a further embodiment, the expandable last further comprisesa lid, to which the core support element and the expandable shell aremounted. The lid provides for an effective way to fix a positionalrelationship between the core support element and the expandable shell,while still allowing the two elements to move with respect to each otherin portions thereof. While the positional relationship between the coresupport element and the expandable shell may be fixed at one endthereof, the expandable shell is free to expand and move away from thecore support element over a large portion thereof. When the last isinserted into the footwear and the footwear is placed on a table orother horizontal structure in its normal use orientation, the coresupport element and the expandable shell extend downwards from the lid.In this way, the lid may form an upper end portion of the expandablelast, when inserted into the footwear in a normal shoe orientation. Thisexplanation of the relative position of the lid and the core supportelement/expandable shell does not preclude the lid to be a side portionor a lower portion of the expandable last, when used for furnishingfootwear with an insert. In other words, the expandable last may bepositioned upside down, i.e. lid down, at selected times or duringsubstantially the entire operation of providing the footwear with theinsert.

According to a further embodiment, the liquid port is arranged in thelid. In this way, the lid is also the structure of the expandable lastthat provides for the connection point to the external liquid source. Inparticular, the liquid port may be arranged in the lid in such a mannerthat the external liquid source/an external liquid supply line may beattached to the lid. The liquid port may extend through the lid.

According to a further embodiment, the lid has an extensionsubstantially corresponding to a transverse cross-section of the collarof the footwear. In this way, the lid may have a sufficient extensionfor mounting the core support element, the expandable shell and, ifdesired, the liquid port thereto. Also, the expandable shell may bemounted to the lid around a peripheral region thereof. In this way, theexpandable shell may immediately engage with the insert on the inside ofthe footwear upon receiving liquid in the liquid chamber.

According to a further embodiment, the expandable last further comprisesa heater configured to heat the liquid in the liquid chamber and/or toheat the expandable shell. By heating the liquid and/or the expandableshell, the heater may contribute to the expansion of the liquid and/ormay provide a warming/heating of the insert. Such warming/heating of theinsert may help in positioning the insert by making the same morepliable and/or may help in attaching the insert to the inside of thefootwear, for example by activating a heat-activated adhesive on theinsert. The heater may be an electric heater that may have a powersupply line to an external power source. The heater may also have arechargeable power source, such as a rechargeable battery, which mayallow the heater to at least temporarily operate without being coupledto an external power supply.

According to a further embodiment, the expandable last comprises anexternal heater configured to heat the liquid before being introducedinto the liquid chamber. In this way, above described beneficial effectsof using heated liquid in the liquid chamber may be achieved, whilekeeping the core support element/liquid chamber free of heatingfunctionality. The external heater may be arranged at a more easilyaccessible location and may be designed/operated without the constraintsassociated with the interior of the footwear.

According to a further embodiment, the expandable last is configured forfurnishing the footwear with a waterproof, breathable bootie. In thisway, the footwear may be made waterproof with the help of the expandablelast. As discussed above, the expandable last may help in making thefootwear waterproof at a late stage of the assembly, in particular at apoint in time when the collar of the footwear is the only access pointto the interior of the footwear. The waterproof, breathable bootie maybe embodied in accordance with any of the embodiments, as described inPCT/EP2017/068030 and/or PCT/EP2018/084179, the contents of which areincorporated herein by reference in their entirety.

According to a further embodiment, the expandable last is configured forfurnishing the footwear with a waterproof, breathable bootie, whereinthe waterproof, breathable bootie is provided, on its outside, withpressure sensitive adhesive and/or heat-activated adhesive forattachment to the inside of the footwear. The pressure sensitiveadhesive and/or heat-activated adhesive may be provided on selectedportions of the outside of the waterproof, breathable bootie or may beprovided substantially all over the outside of the waterproof,breathable bootie. The pressure sensitive adhesive and/or heat-activatedadhesive may be provided as a continuous adhesive layer or as anadhesive pattern, such as a dot or stripe pattern. The expandable lastmay be particularly suitable for inserting the waterproof, breathablebootie provided with adhesive, because the risk of the adhesive gettingstuck in undesired positions during the insertion of the expandable lastcan be kept small by inserting the expandable last in an un-expandedstate together with the waterproof, breathable bootie. It is pointed outthat it is also possible to insert the waterproof, breathable bootieinto the footwear with a separate device and to subsequently use theexpandable last for exerting the pressure onto the insert towards aninside of the footwear. Further, the attachment between the waterproof,breathable bootie and the inside of the footwear may be supplementedwith an adhesive tape in a collar region of the footwear. An adhesivetape in the collar region of the footwear may also provide for a cleanfinish, blocking the upper edge of the insert from view and preventingdelamination of a multi-layer insert from the upper edge. The termheat-activated adhesive refers to an adhesive that has the capacity tobe activated by heat. The heat-activated adhesive may also be referredto as heat-activatable adhesive.

Exemplary embodiments of the invention further include an expandablelast for furnishing footwear with an insert, comprising: an expansionassembly; an expandable shell, arranged around the expansion assembly;and a liquid chamber within the expandable shell; wherein the expandablelast is insertable into the footwear through a collar of the footwearand wherein the expandable shell is configured to expand for pressingthe insert towards an inside of the footwear; and wherein the expansionassembly is configured to adapt its extension for exerting localizedpressure onto the expandable shell towards the inside of the footwear.Exemplary embodiments of the expandable last, having an expansionassembly and an expandable shell, provide an alternative tool foreffectively furnishing footwear with an insert, as compared to abovedescribed exemplary embodiments, having a form-stable core supportelement and an expandable shell. Above described additional features,modifications, and effects are applicable to the expandable last, havingan expansion assembly and an expandable shell, in an analogous manner,as long as they are not conceptually excluded by the expansion assembly.

According to exemplary embodiments of the invention, the expandable lastcomprises an expansion assembly and an expandable shell, arranged aroundthe expansion assembly. In this way, the expandable last may combine alocalized exertion of pressure onto particular portions of theexpandable shell via the expansion assembly with a more uniform exertionof pressure onto the insert via the liquid in the liquid chamber. A goodcompromise between uniform exertion of pressure and localized exertionof pressure may be achieved. Also, the localized exertion of pressuremay achieve a pre-shaping of the expandable shell and may thus allow fora particularly good positioning of the insert with respect to the insideof the footwear. Further, the expansion assembly may also provide forcore support to the expandable last.

According to a further embodiment, the expansion assembly comprises atleast one of a hydraulically operated piston, a pneumatically operatedpiston, an electrically operate piston, and a spring-loaded piston forexerting the localized pressure. With each of the hydraulically operatedpiston, the pneumatically operated piston, and the electrically operatedpiston, an active and highly granular exertion of localized pressure maybe possible. With the spring-loaded piston, an external control andpower supply may be dispensed with and an effective exertion oflocalized pressure may be achieved with comparably less complexity. Inparticular, the spring-loaded piston may allow for the expansionassembly to exert localized pressure without a complex interactionbetween the piston and an external control/power entity.

According to a further embodiment, the expansion assembly comprises abase plate, to which said at least one of a hydraulically operatedpiston, a pneumatically operated piston, an electrically operatedpiston, and a spring-loaded piston is mounted. In this way, the pistonmay have a well-defined travel path with respect to the base plate,which in turn may allow for a well-defined travel path with respect tothe footwear. The base plate may allow for a well-definedarrangement/positioning of the expansion assembly within the footwear.

According to a further embodiment, the spring-loaded piston comprises atleast one of a coil spring and a gas spring. In particular, thespring-loaded piston may comprise a coil spring or a gas spring.

According to a further embodiment, the expansion assembly is configuredto exert localized pressure onto at least one of a toe portion and aheel portion of the expandable shell. In this way, the expansionassembly may be particularly suitable for exerting localized pressure inthe front and/or the rear of the expandable shell. This in turn mayallow for achieving a good longitudinal positioning, stretching, and/orattaching of the insert to the inside of the footwear. The expansionassembly may thus work similar to a shoe tree and may ensure that theinsert is arranged over the full length of the inside of the footwear.

According to a further embodiment, the expansion assembly comprises aspring skeleton having a forefoot spring portion, configured to exertlocalized pressure onto at least one of a toe portion and an instepportion of the expandable shell and having a heel spring portion,configured to exert localized pressure onto a heel portion of theexpandable shell. With the spring skeleton, localized pressure may beexerted onto crucial portions of the insert in a particularly effectivemanner. The spring skeleton may be an elastic spring structure,resembling a foot outline/a foot skeleton in its longitudinal direction.The expandable shell may be conformed to some extent to the generalshape of a human foot, while leaving ample room for the liquid withinthe expandable shell to provide for uniform exertion of pressure ontothe expandable shell. Again, a good compromise between uniform exertionof pressure and localized exertion of pressure may be achieved. Thespring skeleton may work similar to a shoe tree and may provide adesired stretching of the expandable shell at the toe portion and/or theinstep portion and/or the heel portion of the expandable shell.

According to a further embodiment, the spring skeleton is made of metal,in particular made of steel. According to an alternative embodiment, thespring skeleton is made of composite material, in particular made offiber-reinforced plastics material. The spring skeleton may be made froman elastic synthetic material. It may also be made from a memory alloyor bimetal. It is also possible that the spring skeleton is made from acombination of parts of different materials, in particular from acombination of metal parts and composite material parts. Further, it ispossible that pressure exertion pads are provided at the spring skeletonfor exerting the localized pressure. The pressure exertion pads may bemade from a different material, such as from a plastics material, inparticular a plastics material that is softer than the material of thespring skeleton, or from a padding material.

According to a further embodiment, the forefoot spring portion isconfigured to force its forefoot end portion in a forward and upwarddirection. In this way, a particularly good stretching of the insertand/or a particularly good attachment between the insert and the toeportion of the footwear, which may be difficult due to theirregularities of the inner contour in the toe portion and/or due to thecomparably stiff nature of the toe portion of the footwear, may beachieved in an effective manner. The upward component of the force,exerted by the forefoot end portion of the forefoot spring portion, maybe particularly effective in achieving an overall strong attachmentbetween the insert and the toe portion of the footwear.

According to a further embodiment, the forefoot spring portion has awaved shaped, with a first exposed portion exerting localized pressureonto the instep portion of the expandable shell and with a secondexposed portion exerting localized pressure onto the toe portion of theexpandable shell. The waved shaped of the forefoot spring portionprovides for a particular effective way of exerting localized pressureonto both the toe portion of the expandable shell and the instep portionof the expandable shell. With the waved shape, a balanced exertion oflocalized pressure between the instep portion and the toe portion of theexpandable shell may be achieved. The waved shape may be particularlywell-suited for providing localized pressure in the forefoot portion ofthe expandable last. The second exposed portion may in particular be theforefoot end portion, as described above, and may in particular beconfigured as being forced in a forward and upward direction.

According to a further embodiment, the forefoot spring portion comprisesan instep spring element, extending along the instep portion of theexpandable shell and having its free end pointing rearwards. The instepspring element may in particular extend along the instep portion of theexpandable shell and may have its free end pointing in a rearward andupward direction. With such a dedicated instep spring element, localizedpressure may be exerted particularly well onto the instep portion of theexpandable shell. While the instep spring element is seen as part of theforefoot spring portion, it is an element that extends away from thatpart of the forefoot spring portion that extends between a collar regionof the expandable last and the forefoot end portion of the forefootspring portion. Via this extending away, the instep spring element has afree end pointing rearwards. With the instep spring element having itsfree end pointing rearwards, the forefoot spring portion may beeffectively designed to provide the localized pressure onto the toeportion of the expandable shell and to provide the localized pressureonto the instep portion of the expandable shell in a highly targetedmanner, taking into account the particulars of the toe portion and theinstep portion in a particularly effective manner.

According to a further embodiment, the heel spring portion is configuredto force its heel end portion in a rearward and upward direction. Inthis way, an attachment between the insert and the heel portion of thefootwear, which may be difficult due to the particular shape of heelconstructions of footwear, may be achieved in an effective manner. Inparticular, the upward component of the force of the heel end portiontowards the expandable shell/towards the insert may be particularlyeffective in contributing to said attachment.

According to a further embodiment, the expansion assembly comprises aform-stable core support element. The form-stable core support elementmay in particular be substantially L-shaped or substantially T-shaped.The form-stable core support element may provide for enhanced stabilityfor the spring skeleton of the expansion assembly. The form-stable coresupport element may in particular reach to a sole portion of theexpandable shell. It may thus provide an effective positioning of theexpandable shell in a downwards portion of the expandable last. Inparticular, the form-stable core support element may counter potentialupward components of the force exerted by the forefoot end portionand/or the heel end portion of the spring skeleton. It may thuscontribute to a multi-directional stretching of the expandable shell.

According to a further embodiment, the expandable last further comprisesa lid, to which the expandable shell is mounted. In a particularembodiment, the expansion assembly is fixed in position with respect tothe lid. For example, the expansion assembly may be mounted to the lidvia a mounting rod. In this way, an effective positioning of theexpansion assembly with respect to the collar of the footwear may beachieved. Also, core support to the expandable last may be achieved inan effective manner, similar to the core support element, discussedabove.

According to a further embodiment, the spring skeleton is mounted to thelid. It is also possible that the spring skeleton is mounted to a coresupport element, which is in turn mounted to the lid. It is alsopossible that both the spring skeleton and a core support element aremounted to the lid.

According to a further embodiment, the expansion assembly is attached tothe expandable shell. In this case, the expansion assembly may beun-attached to the lid or may be attached to the lid in addition to theattachment to the expandable shell. The attachment between the expansionassembly and the expandable shell may provide for a particularlywell-defined exertion of localized pressure by the expansion assembly.

According to a further embodiment, the expandable last further comprisesa liquid port, providing liquid communication between the liquid chamberand an external liquid source, wherein the expandable shell isconfigured to expand for pressing the insert towards an inside of thefootwear, when receiving liquid in the liquid chamber via the liquidport. In this way, in addition to the localized pressure exerted by theexpansion assembly, the more uniform pressure via the liquid chamber isprovided via the reception of liquid from an external liquid source.

According to a further embodiment, the expandable last further comprisesa heater arranged in the liquid chamber, wherein the heater isconfigured to heat liquid in the liquid chamber for expanding theexpandable shell and pressing the insert towards an inside of thefootwear via an increase in volume of the liquid in the liquid chamber.In this way, in addition to the localized pressure exerted by theexpansion assembly, the more uniform pressure via the liquid chamber isprovided by an increase in volume of the liquid due to the heatingthereof. In this way, the exertion of the more uniform pressure may beachieved without a liquid port and without increasing the amount ofliquid in the liquid chamber.

According to a further embodiment, the heater is an electric heater. Theelectric heater may be coupled to an external power supply via a powersupply line. The power supply line may run through the lid. It is alsopossible that the heater comprises a rechargeable power source, such asa rechargeable battery.

According to a further embodiment, the expansion assembly and the heaterare fixed in position with respect to each other. In a particularembodiment, the expansion assembly and the heater are formed as anintegrated structural unit. In this way, the expandable last may have ahigh degree of inherent stability and may be handled in a particularlyconvenient manner.

According to a further embodiment, the expandable last further comprisesa lid, to which the expandable shell is mounted. The expansion assemblyand/or the heater may also be mounted to the lid. In particular, theexpansion assembly and the heater may be mounted to the lid as anintegrated structural unit.

According to a further embodiment, the expandable shell and the lid forma liquid-tight enclosure. In particular, the lid and the expandableshell may be free of a liquid port. The lid and the expandable shellbeing free of a liquid port is to be understood in a way that no liquidcommunication between the liquid chamber and an outside of theexpandable last takes place in the expansion operation, i.e. during theapplication of pressure to the insert via the expandable shell. Theliquid-tight enclosure may keep the amount of liquid within the liquidchamber fixed, and the expansion of the expandable shell may be solelycaused by the heating of the liquid within the liquid chamber. This doesnot exclude the provision of suitable means for filling and evacuatingliquid into/from the liquid chamber between such normal operations. Forexample, the liquid may be exchanged after a certain number of expansionoperations, e.g. for cleaning, maintaining the heater, for preventingliquid depositions on the expandable shell, etc.

According to a further embodiment, the expandable last may be combinedwith an external heater, such as an electric oven or microwave oven. Inparticular, an embodiment of the invention may be the combination of theexpandable last and an external heater, into which the expandable lastmay be placed together with the footwear. In this way, the expandablelast and the footwear may be jointly heated, and the heating action,described above with respect to the heater within the expandable last,may take place as a result of the external heating.

The expandable last, having an expansion assembly and an expandableshell, as described with respect to any of the embodiments above, mayadditionally have any of the following features, alone or in anycombination:

The liquid chamber comprises substantially the entire volume between theexpansion assembly and the expandable shell.

The expandable shell is elastic, in particular made from latex material.

The expandable shell has, at least in one or more regions thereof,dimension-specific elastic properties.

The liquid chamber is at least partly filled with an open-cell foam, inparticular with an open-cell polyurethane foam, and/or with a spacerfabric.

The expandable last further comprises at least one expandable liquidbag, arranged outside or inside of the expandable shell.

The expandable last further comprises at least one ancillary liquidport, providing liquid communication between the at least one expandableliquid bag and at least one external liquid source.

The expandable last further comprises at least one ancillary liquidsupply line, coupling the at least one expandable liquid bag to the atleast one ancillary liquid port, wherein the at least one ancillaryliquid supply line in particular runs through the liquid chamber.

The at least one expandable liquid bag comprises at least one of: anexpandable liquid bag at an instep portion of the expandable shell; anexpandable liquid bag at a toe portion of the expandable shell; anexpandable liquid bag in a forefoot portion of the expandable shell; anexpandable liquid bag in an upper midfoot portion of the expandableshell.

The at least one expandable liquid bag is at least partly filled with anopen-cell foam, in particular with an open-cell polyurethane foam,and/or with a spacer fabric.

The liquid port is arranged in the lid.

The lid has an extension substantially corresponding to a transversecross-section of the collar of the footwear.

Exemplary embodiments of the invention further include an expandablelast for furnishing footwear with an insert, comprising: an expandableshell; a liquid chamber within the expandable shell; and a liquid port,providing liquid communication between the liquid chamber and anexternal liquid source; wherein the expandable last is insertable intothe footwear through a collar of the footwear and wherein, whenreceiving liquid in the liquid chamber via the liquid port, theexpandable shell is configured to expand for pressing the insert towardsan inside of the footwear; and wherein the expandable shell has, atleast in one or more regions thereof, dimension-specific elasticproperties. Exemplary embodiments of the expandable last, whoseexpandable shell has dimension-specific elastic properties, provide analternative tool for effectively furnishing footwear with an insert, ascompared to above described exemplary embodiments of expandable lasts.Above described additional features, modifications, and effects areapplicable to the expandable last, whose expandable shell hasdimension-specific elastic properties, in an analogous manner, as longas they are not conceptually excluded by the expandable shell havingdimension-specific elastic properties.

With the expandable shell having dimension-specific elastic properties,the course of expansion of the expandable shell can be controlled and aparticularly effective exertion of pressure onto the insert may beachieved. For example, the dimension-specific elastic properties mayallow for the expandable shell to first assume a desired coarse shape,before exerting a highly uniform pressure onto the insert. By havingdimension-specific elastic properties, the expandable shell reacts topressure increases differently in at least two dimensions. Thedimensions may be dimensions defined in a cartesian coordinate system ormay be dimensions suitably defined in the context of a substantiallyfoot-shaped last, such as a longitudinal dimension of the expandableshell and a circumferential dimension of the expandable shell.

According to a further embodiment, the expandable shell hasdimension-specific elastic properties in at least one of a midfootportion and a forefoot portion of the expandable shell. In this way, aparticularly good adaptation to the footwear shape may be achieved.Also, a good adaptation to footwear of different sizes may be achieved.In this way, the expandable last may be used for footwear ofconsiderably different sizes.

According to a further embodiment, the expandable shell is configured toexpand more easily in a longitudinal dimension than a circumferentialdimension in at least one of a midfoot portion and a forefoot portion.In this way, the expandable shell may first expand in the longitudinaldimension, before expanding in the circumferential dimension. This inturn may allow for the expandable last to first cover the full length ofthe longitudinal dimension of the footwear, before exerting pressurearound the circumference of the expandable last. Such a behaviour mayhelp in positioning the insert/keeping the insert in position in aparticularly targeted manner, before applying all around pressure. Theterminology of the expandable shell being configured to expand moreeasily in the longitudinal dimension than in the circumferentialdimension means that the expandable shell expands in the longitudinaldimension earlier and/or at a lower fluid pressure than in thecircumferential dimension.

According to a further embodiment, the expandable last is free of aform-stable core support element and/or free of an expansion assembly,arranged within the expandable shell. In other words, the exertion ofpressure onto the insert may be achieved solely by the provision of anexpandable shell with dimension-specific elastic properties and thebuilding-up of pressure within the liquid chamber via liquid receivedthrough the liquid port.

The expandable last, having an expandable shell with dimension-specificelastic properties, as described with respect to any of the embodimentsabove, may additionally have any of the following features, alone or inany combination:

The liquid chamber comprises substantially the entire volume within theexpandable shell.

The expandable shell is made from latex material.

The liquid chamber is at least partly filled with an open-cell foam, inparticular with an open-cell polyurethane foam, and/or with a spacerfabric.

The expandable last further comprises at least one expandable liquidbag, arranged outside or inside of the expandable shell.

The expandable last further comprises at least one ancillary liquidport, providing liquid communication between the at least one expandableliquid bag and at least one external liquid source.

The expandable last further comprises at least one ancillary liquidsupply line, coupling the at least one expandable liquid bag to the atleast one ancillary liquid port, wherein the at least one ancillaryliquid supply line in particular runs through the liquid chamber.

The at least one expandable liquid bag comprises at least one of: anexpandable liquid bag at an instep portion of the expandable shell; anexpandable liquid bag at a toe portion of the expandable shell; anexpandable liquid bag in a forefoot portion of the expandable shell; anexpandable liquid bag in an upper midfoot portion of the expandableshell.

The at least one expandable liquid bag is at least partly filled with anopen-cell foam, in particular with an open-cell polyurethane foam,and/or with a spacer fabric.

The expandable last further comprises a lid, to which the expandableshell is mounted.

The liquid port is arranged in the lid.

The lid has an extension substantially corresponding to a transversecross-section of the collar of the footwear.

The expandable last further comprises a heater, configured to heat theliquid in the liquid chamber and/or to heat the expandable shell.

Exemplary embodiments of the invention further include an expandablelast for furnishing footwear with an insert, comprising: a rigid lastportion; an expandable shell, arranged adjacent to the rigid lastportion; a liquid chamber within the expandable shell; and a liquidport, providing liquid communication between the liquid chamber and anexternal liquid source; wherein the expandable last is insertable intothe footwear through a collar of the footwear and wherein, whenreceiving liquid in the liquid chamber via the liquid port, theexpandable shell is configured to expand for pressing the insert towardsan inside of the footwear. Exemplary embodiments of the expandable last,having a rigid last portion and an expandable shell adjacent to therigid last portion, provide an alternative tool for effectivelyfurnishing footwear with an insert, as compared to above describedexemplary embodiments of expandable lasts. Above described additionalfeatures, modifications, and effects are applicable to the expandablelast, having a rigid last portion and an expandable shell adjacent tothe rigid last portion, in an analogous manner, as long as they are notconceptually excluded by the combination of the rigid last portion andthe expandable shell.

According to exemplary embodiments of the invention, the expandable lastcomprises a rigid last portion and an expandable shell, arrangedadjacent to the rigid last portion. The rigid last portion may providefor an effective exertion of pressure in portions of the footwear wheregood results may be achieved with a rigid structure. In turn, theexpandable shell may have smaller extensions and may thus provide thedesired highly uniform pressure with a lower amount of liquid. Theflexibility of the expandable shell may be combined with the lowcomplexity of a rigid last portion in a beneficial manner.

The expandable last may also comprise a plurality of rigid last portionsand/or a plurality of expandable shells. The additional features andmodifications, as described herein, are applicable to one or a subset orall of the plurality of rigid last portions and/or to one or a subset ofall of the plurality of expandable shells.

According to a further embodiment, the rigid last portion is made frommetal, such as aluminum. Metal may provide for a highly rigid structureof the last portion and may be a good heat conductor, in case the rigidlast portion is heated and/or in case the liquid in the liquid chamberis heated. Aluminum provides for a good compromise between thebeneficial properties of metal and a comparably low weight. The rigidlast portion may also be made from other suitable materials, such asheat resistant plastic.

According to a further embodiment, the rigid last portion is heatable.In this way, the rigid last portion may be used for heating the liquidin the liquid chamber of the expandable last and may thus contribute tothe expansion of the expandable shell. Also, the rigid last portion mayapply heat to the insert and may thus help in attaching the insert tothe inside of the footwear, for example by activating a heat-activatedadhesive on the insert. In addition/alternatively, the rigid lastportion may be thermally conductive, being configured to conduct heat tothe insert from heated liquid in the liquid chamber.

According to a further embodiment, the expandable last comprises a rigidforefoot and instep last portion and a rigid heel last portion, whereinthe expandable shell is arranged between the rigid forefoot and insteplast portion and the rigid heel last portion. In this way, theexpandable last comprises a so-called split last, having a front rigidlast portion and a rear rigid last portion. The space between the rigidforefoot and instep last portion and the rigid heel last portion may bepartly or substantially entirely filled with the expandable shell, atleast when in an expanded state. In this way, a highly uniform pressuremay be applied to a midfoot portion and/or ankle portion of the insideof the footwear, while the front and rear rigid last portions exertpressure onto the forefoot portion and the heel portion of the inside ofthe footwear.

According to a further embodiment, the rigid forefoot and instep lastportion and the rigid heel last portion are movable with respect to eachother and the expandable last comprises an actuator for controlling aspacing between the rigid forefoot and instep last portion and the rigidheel last portion. In this way, the expandable last may be adapted tothe footwear in question, in particular adapted to the shoe size of thefootwear in question. Further, the expandable last may be controlled toexert a desired pressure onto the front portion and the heel portion ofthe inside of the footwear in this manner. Also, the insertion of theexpandable last into the footwear may be carried out in a particularlyconvenient manner, when the rigid forefoot and instep last portion andthe rigid heel last portion have a low spacing therebetween. Theactuator may be a pneumatic actuator or a hydraulic actuator or anelectric actuator.

According to a further embodiment, the expandable last comprises atleast one expandable liquid bag, arranged on an outside of the rigidlast portion. As discussed above, a localized adaption of the pressureexerted onto the insert towards the inside of the footwear may beachieved in this manner.

According to a further embodiment, the at least one expandable liquidbag comprises at least one expandable liquid bag in a toe region and/orin a heel region of the expandable last, in particular an expandableliquid bag in a toe region of the rigid forefoot and instep last portionof the expandable last. The term toe region may refer to an upper sideof the toe region of the expandable last or to a lower side of the toeregion of the expandable last or to a joint upper and lower side of thetoe region, reaching around the tip of the expandable last.

The expandable last, having a rigid last portion and an expandableshell, arranged adjacent to the rigid last portion, as described withrespect to any of the embodiments above, may additionally have any ofthe following features, alone or in any combination:

The liquid chamber comprises substantially the entire volume within theexpandable shell.

The expandable shell is elastic, in particular made from latex material.

The expandable shell has, at least in one or more regions thereof,dimension-specific elastic properties.

The liquid chamber is at least partly filled with an open-cell foam, inparticular with an open-cell polyurethane foam, and/or with a spacerfabric.

The expandable last further comprises at least one ancillary liquidport, providing liquid communication between the at least one expandableliquid bag and at least one external liquid source.

The expandable last further comprises at least one ancillary liquidsupply line, coupling the at least one expandable liquid bag to the atleast one ancillary liquid port, wherein the at least one ancillaryliquid supply line in particular runs through the liquid chamber.

The at least one expandable liquid bag is at least partly filled with anopen-cell foam, in particular with an open-cell polyurethane foam,and/or with a spacer fabric.

The expandable last further comprises a lid, to which the expandableshell is mounted.

The liquid port is arranged in the lid.

Exemplary embodiments of the invention further include an expandablelast for furnishing footwear with an insert, comprising: an expandableshell; a granulate chamber within the expandable shell; and a granulateport, providing a granulate channel between the granulate chamber and anexternal granulate source; wherein the expandable last is insertableinto the footwear through a collar of the footwear and wherein, whenreceiving granulate in the granulate chamber via the granulate port, theexpandable shell is configured to expand for pressing the insert towardsan inside of the footwear. The granulate port may in particular beconfigured for providing a granulate channel between the granulatechamber and an external heated granulate source. Exemplary embodimentsof the expandable last, having a granulate chamber within an expendableshell and a granulate port for receiving granulate within the granulatechamber, provide an alternative tool for effectively furnishing footwearwith an insert, as compared to above described exemplary embodiments ofexpandable lasts. Above described additional features, modifications andeffects are applicable to the expandable last, having a granulatechamber within an expandable shell, in an analogous manner, as long asthey are not conceptually excluded by the combination of the granulatechamber and the expandable shell.

With the granulate chamber within the expandable shell and the granulateport, the expandable last may be conveniently introduced into theinterior of the footwear and the expandable shell may exert pressureonto the insert with a high degree of uniformity upon receivinggranulate within the granulate chamber. Relying on granulate forexerting pressure onto the insert with a high degree of uniformity, theexpandable last may work similar to above described expandable lasts,without relying on liquid as the pressure exerting medium. In this way,the footwear may be kept free of damage, in case the expandable shell ispunctured or torn during the furnishing of the footwear with an insert,as described herein. Heated granulate, for example received from anexternal heated granulate source, may help in attaching the insert tothe inside of the footwear, for example by activating a heat-activatedadhesive on the insert.

The expandable last, having a granulate chamber within an expandableshell, as described with respect to any of the embodiments above, mayadditionally have any of the following features, alone or in anycombination:

The granulate chamber comprises substantially the entire volume withinthe expandable shell.

The expandable shell is elastic.

The expandable shell is made from latex material.

The expandable shell is made of synthetic material, in particular of atextile material. The expandable shell may for example by a nylon sock.

The expandable shell has, at least in one or more regions thereof,dimension-specific elastic properties.

The expandable last further comprises at least one expandable liquidbag, arranged outside or inside of the expandable shell.

The expandable last further comprises at least one ancillary liquidport, providing liquid communication between the at least one expandableliquid bag and at least one external liquid source.

The expandable last further comprises at least one ancillary liquidsupply line, coupling the at least one expandable liquid bag to the atleast one ancillary liquid port, wherein the at least one ancillaryliquid supply line in particular runs through the granulate chamber.

The at least one expandable liquid bag comprises at least one of: anexpandable liquid bag at an instep portion of the expandable shell; anexpandable liquid bag at a toe portion of the expandable shell; anexpandable liquid bag in a forefoot portion of the expandable shell; anexpandable liquid bag in an upper midfoot portion of the expandableshell.

The at least one expandable liquid bag is at least partly filled with anopen-cell foam, in particular with an open-cell polyurethane foam,and/or with a spacer fabric.

The granulate port is arranged in the lid.

The lid has an extension substantially corresponding to a transversecross-section of the collar of the footwear.

The expandable last further comprises a heater, configured to heat thegranulate in the granulate chamber and/or to heat the expandable shell.

The expandable last further comprises a form-stable core supportelement, in particular a substantially L-shaped or substantiallyT-shaped core support element.

It is also possible that the granulate is introduced into the insertwithout an interposed expandable shell. The granulate may be introducedinto the insert, before the insert is placed within the footwear and/orwhen the insert is positioned in the footwear, and an exertion ofpressure onto the insert may be achieved via controlling the amount ofgranulate within the insert and/or the temperature of the granulate.

Exemplary embodiments of the invention further include a method forfurnishing footwear with an insert using an expandable last, asdescribed herein. The expandable last may be embodied in accordance withany of the embodiments, described above. The additional features,modifications, and effects, described above with respect to theexpandable last, apply to the method for furnishing footwear with aninsert in an analogous manner.

According to a further embodiment, the insert is a waterproof,breathable bootie. In this way, the method for furnishing footwear withan insert may also be referred to as a method for waterproofingfootwear.

Exemplary embodiments of the invention further include a method forfurnishing footwear with an insert, the method comprising: inserting anexpandable last into the footwear through a collar of the footwear, theexpandable last having an expandable shell and a liquid chamber withinthe expandable shell; and pressing the insert towards an inside of thefootwear by expanding the expandable shell via liquid in the liquidchamber. The additional features, modifications, and effects, describedabove with respect to the expandable last, apply to the method forfurnishing footwear with an insert in an analogous manner. Inparticular, the expandable last may be embodied in accordance with anyof the embodiments described above.

According to a further embodiment, said expanding of the expandableshell via liquid in the liquid chamber comprises introducing liquid intothe liquid chamber. In particular, the liquid may be introduced via aliquid port in the expandable last from an external liquid source. Anysuitable liquid may be used for expanding the expandable shell. Suitableliquids include water, oils, and thermotransfer fluids, such as 3M Novec7500®.

According to a further embodiment, said expanding of the expandableshell via liquid in the liquid chamber comprises introducing heatedliquid into the liquid chamber. In particular, the liquid may beintroduced at a temperature between 60° C. and 200° C. The temperaturemay depend on the liquid used. For example, water may be introduced at atemperature of between 60° C. and 95° C. The term heated liquid mayrefer to liquid being warmer than room temperature, in particular liquidhaving at least 30° C.

According to a further embodiment, said expanding of the expandableshell via liquid in the liquid chamber comprises heating the liquid inthe liquid chamber. In particular, the liquid may be heated via a heaterarranged within the expandable shell.

According to a further embodiment, the insert is a waterproof,breathable bootie. In this way, the method for furnishing footwear withan insert may also be referred to as a method for waterproofingfootwear.

According to a further embodiment, the inserting of the expandable lastinto the footwear through a collar of the footwear comprises insertingthe expandable last into an inner space of the footwear, after the innerspace of the footwear has been closed, e.g. after the footwear has beenlasted and the sole has been applied. The inserting of the expandablelast into the footwear may take place when the footwear is otherwisefully assembled or substantially fully assembled.

According to a further embodiment, the pressing of the insert towardsthe inside of the footwear comprises attaching/adhering the insert tothe inside of the footwear.

Exemplary embodiments of the invention further include a method forfurnishing footwear with an insert, the method comprising: inserting anexpandable last into the footwear through a collar of the footwear, theexpandable last having an expandable shell and a granulate chamberwithin the expandable shell; and pressing the insert towards an insideof the footwear by expanding the expandable shell via granulate in thegranulate chamber. The additional features, modifications, and effects,described above with respect to the expandable last and with respect tothe method for furnishing footwear with an insert by expanding theexpandable shell via liquid, apply to the method for furnishing footwearwith an insert by expanding the expandable shell via granulate in ananalogous manner. In particular, the expandable last may be embodied inaccordance with any of the embodiments described above.

It is pointed out that exemplary embodiments of the expandable last, asdescribed herein, may also be used for other purposes than furnishingfootwear with an insert. In particular, the expandable last may also beused at an earlier stage in the production of footwear. For example, theexpandable last according to exemplary embodiments of the invention maybe used for lasting a shoe upper thereon. The expandable lasts inaccordance with the following definitions also form part of the subjectmatter of the present invention.

Exemplary embodiments of the invention further include an expandablelast, comprising: a form-stable core support element; an expandableshell, arranged around the core support element; a liquid chamber withinthe expandable shell; and a liquid port, providing liquid communicationbetween the liquid chamber and an external liquid source; wherein, whenreceiving liquid in the liquid chamber via the liquid port, theexpandable shell is configured to expand.

Exemplary embodiments of the invention further include an expandablelast, comprising: an expansion assembly; an expandable shell, arrangedaround the expansion assembly; and a liquid chamber within theexpandable shell; wherein the expandable shell is configured to expand;and wherein the expansion assembly is configured to adapt its extensionfor exerting localized pressure onto the expandable shell.

Exemplary embodiments of the invention further include an expandablelast, comprising: an expandable shell; a liquid chamber within theexpandable shell; and a liquid port, providing liquid communicationbetween the liquid chamber and an external liquid source; wherein, whenreceiving liquid in the liquid chamber via the liquid port, theexpandable shell is configured to expand; and wherein the expandableshell has, at least in one or more regions thereof, dimension-specificelastic properties.

Exemplary embodiments of the invention further include an expandablelast, comprising: a rigid last portion; an expandable shell, arrangedadjacent to the rigid last portion; a liquid chamber within theexpandable shell; and a liquid port, providing liquid communicationbetween the liquid chamber and an external liquid source; wherein, whenreceiving liquid in the liquid chamber via the liquid port, theexpandable shell is configured to expand.

Exemplary embodiments of the invention further include an expandablelast, comprising: an expandable shell; a granulate chamber within theexpandable shell; and a granulate port, providing a granulate channelbetween the granulate chamber and an external granulate source; whereinthe expandable last is insertable into the footwear through a collar ofthe footwear and wherein, when receiving granulate in the granulatechamber via the granulate port, the expandable shell is configured toexpand for pressing the insert towards an inside of the footwear.

The additional features, modifications, and effects, described abovewith respect to exemplary embodiments of the expandable last in thecontext of furnishing footwear with an insert, apply to the exemplaryembodiments of the expandable last of the preceding five paragraphs inan analogous manner.

Further exemplary embodiments of the invention will be described belowwith reference to the accompanying drawings, wherein:

FIG. 1 shows an expandable last in accordance with a first exemplaryembodiment of the invention in a longitudinal cross-sectional view;

FIG. 2 shows an expandable last in accordance with a second exemplaryembodiment of the invention in a longitudinal cross-sectional view;

FIG. 3 shows an expandable last in accordance with a third exemplaryembodiment of the invention in a longitudinal cross-sectional view;

FIG. 4A shows an expandable last in accordance with a fourth exemplaryembodiment of the invention in a longitudinal cross-sectional view, andFIG. 4B shows a modification thereof in a longitudinal cross-sectionalview;

FIG. 5 shows an expandable last in accordance with a fifth exemplaryembodiment of the invention in a longitudinal cross-sectional view;

FIG. 6 shows an expandable last in accordance with a sixth exemplaryembodiment of the invention in a longitudinal cross-sectional view;

FIG. 7 shows an expandable last in accordance with a seventh exemplaryembodiment of the invention in a longitudinal cross-sectional view;

FIG. 8 shows an expandable last in accordance with an eight exemplaryembodiment of the invention in a longitudinal cross-sectional view;

FIG. 9 shows an expandable last in accordance with a ninth exemplaryembodiment of the invention in a longitudinal cross-sectional view;

FIG. 10 illustrates a method for furnishing footwear with an insert inaccordance with an exemplary embodiment of the invention, the methodusing an expandable last according to an exemplary embodiment of theinvention;

FIG. 11 shows an expandable last in accordance with a tenth exemplaryembodiment of the invention in a longitudinal cross-sectional view;

FIG. 12 shows an expandable last in accordance with an eleventhexemplary embodiment of the invention in a longitudinal cross-sectionalview; and

FIG. 13 shows an expandable last in accordance with a twelfth exemplaryembodiment of the invention in a longitudinal cross-sectional view.

FIG. 1 shows an expandable last 2 in accordance with a first exemplaryembodiment of the invention in a schematic longitudinal cross-sectionalview. When imagining the expandable last 2 arranged in the interior of afootwear and the footwear being placed on a table or other horizontalstructure in its normal use position, the cross-sectional view of FIG. 1is a vertical cross-sectional view, with the cross-sectional planerunning substantially through the center of the expandable last in thetransverse direction of the footwear. The expandable last 2 may be usedboth for a left shoe and a right shoe. However, it is also possible thatdifferent versions of the expandable last are used for the left shoe andthe right shoe.

The expandable last 2 comprises a form-stable core support element 4. Inthe exemplary embodiment of FIG. 1 , the core support element 4 issubstantially foot-shaped. This means that the core support element 4roughly resembles a human foot, having an ankle portion, a heel portion,a midfoot portion and a forefoot portion. In the exemplary embodiment ofFIG. 1 , the core support element is flexible, made from rubbermaterial. This means that the core support element 4 has someflexibility, which is particularly useful for inserting the expandablelast into the interior of a footwear. In the exemplary embodiment ofFIG. 1 , the core support element 4 is made from resilient rubbermaterial, with the resilience of the rubber material counter-acting adeformation and maintaining the foot shape within the footwear. The coresupport element 4 is considered form-stable, as it does not have anyactive shape adjusting means. Also, its resilience aims as maintainingthe foot shape. Further, while providing some flexibility, the rubbermaterial of the core support element is sufficiently rigid for theexpandable last to not completely loose its shape/undergo a substantialshape transformation during insertion into the footwear.

The expandable last 2 further comprises an expandable shell 6. Theexpandable shell 6 is arranged around the core support element 4.Between the core support element 4 and the expandable shell 6, a liquidchamber 8 is formed. The expandable shell 6 is made from, for example, alatex material and forms the outermost part of the expandable last 2 fora large portion thereof. In particular, the expandable shell 6 forms theoutermost portion of the expandable last 2 in the heel portion, themidfoot portion, the forefoot portion, and part of the ankle portion ofthe expandable last 2. The expandable shell 6 is elastic and can expandupon receiving liquid in the liquid chamber 8.

In the exemplary embodiment of FIG. 1 , the expandable shell 6 isliquid-tight/liquid-proof. Upon receiving liquid, such as water, theexpandable shell 6 contains the liquid in the liquid chamber 8 andexpands as a response to an increasing amount of liquid. The latexmaterial of the expandable shell 6 is inherently liquid-proof, also inan expanded/stretched state. The expandable shell 6 may have one latexlayer. It may also be made of a two-layer or three-layer structure, inparticular a two-layer latex structure or a three-layer latex structure.

The expandable last 2 further comprises a lid 10. The form-stable coresupport element 4 and the expandable shell 6 are mounted to the lid 10.Together, the expandable shell 6 and the lid 10 fully enclose the coresupport element 4 and the liquid chamber 8.

The lid 10 is a substantially rotationally symmetric structure, havingan inner lid portion 12 and an outer lid portion 14. The lid 10 may bemade from plastic or other suitable material. The expandable shell 6 isclamped between the inner lid portion 12 and the outer lid portion 14 ina liquid-tight manner. For additional sealing, a suitable sealing tape,such as a vulcanization tape, may be applied. In this way, no liquid canescape from the liquid chamber 8 through the expandable shell 6 orthrough its connection to the lid 10. The lid 10 has a transversecross-sectional extension that substantially corresponds to thetransverse extension of the collar of a footwear. In particular, thetransverse extension of the lid 10 may correspond to the transverseextension of the collar of the footwear at or above an ankle portionthereof.

The expandable last 2 further comprises a liquid port 16. In theexemplary embodiment of FIG. 1 , the liquid port 16 is part of the lid10. In particular, the liquid port 16 is a duct through the inner lidportion 12. In the exemplary embodiment of FIG. 1 , the liquid port 16is equipped with a valve 18, which allows for liquid to be pressuredinto the expandable last 2 from an external liquid source and whichprevents liquid from flowing back out of the expandable last 2. Whilegenerally preventing liquid from flowing out of the liquid chamber 8,the valve 18 may be manipulated in such a manner that the liquid can beevacuated from the liquid chamber 8.

The core support element 4 comprises a liquid supply line system 20 thatis coupled to the liquid port 16. Liquid from the external liquid sourcemay enter the liquid supply line system 20 via the liquid port 16. Inthe exemplary embodiment of FIG. 1 , the liquid supply line system 20has a substantially vertical liquid supply line, running downwards fromthe liquid port 16, and a substantially horizontal liquid supply line,running from a sole-side end of the substantially vertical liquid supplyline both towards a heel portion of the core support element 4 and aforefoot portion of the core support element 4. The substantiallyhorizontal liquid supply line has two openings 22 towards the liquidchamber 8. In particular, the substantially horizontal liquid supplyline has an opening 22 towards a heel portion of the liquid chamber 8and an opening towards a forefoot portion of the liquid chamber 8. Inthis way, the core support element 4 and its liquid supply line systemare well-suited to distribute the liquid, received by the liquid port16, within the liquid chamber 8.

In use, an insert may be arranged around the expandable shell 6, theexpandable last 2 and the insert may be jointly introduced into afootwear, an external liquid source may be coupled to the liquid port16, liquid, in particular heated liquid may be introduced into theliquid chamber 8 via the liquid port 16 and the liquid supply linesystem 20, the expandable shell 6 may expand as a response to anincreasing amount of liquid in the liquid chamber 8, and the insert maybe pressed against the inside of the footwear. A more detaileddescription of the provision of an insert on the inside of the footwearis given below in FIG. 10 . It is pointed out that said method steps areexemplary only and that other ways of furnishing footwear with an insertmay be implemented with an expandable last in accordance with exemplaryembodiments. For example, it is also possible to place an insert intothe footwear, to fix an upper portion of the insert to a collar regionof the footwear, and to then introduce the expandable last into thejoint structure of footwear and insert. When introducing the expandablelast into the insert, a cover may be placed over the last to protect theinsert and/or the expandable shell from puncturing and to facilitate asmooth insertion of the expandable last into the insert. The cover maybe a sock-like structure, in particular a textile sock-like structure.The introduction of liquid and the ensuing steps may then be carried outas described above. It is pointed out that the cover may also be placedover the expandable last as an intermediate element between theexpandable last and the insert, when the expandable last is used forintroducing the insert into the footwear. In this case, the cover mayallow for a smoother pulling of the insert over the expandable last.

FIG. 2 shows an expandable last 2 in accordance with a second exemplaryembodiment of the invention in a schematic longitudinal cross-sectionalview. Various components of the expandable last 2 of FIG. 2 areidentical/similar to the corresponding components of the expandable last2 of FIG. 1 . They are provided with corresponding reference numerals,and reference is made to their description above. The two maindifferences between the expandable last 2 of FIG. 2 and the expandablelast 2 of FIG. 1 are the design of the core support element 4 and theprovision of an open-cell foam 24 in the liquid chamber 8. Thesedifferences will be discussed in detail below.

The core support element 4 of the expandable last 2 of FIG. 2 issubstantially L-shaped. The two legs of the L-shaped core supportelement 4 are a substantially vertical leg, running from the lid 10 inthe direction of the sole of the expandable last 2, and a substantiallyhorizontal leg, running from a sole-side end of the substantiallyvertical leg towards a forefoot portion of the expandable last 2. TheL-shaped core support element is a stiff structure, made from metal orrigid plastics material.

The liquid supply line system 20 of the core support element 4 of FIG. 2has various branches. In particular, six openings 22 connect the liquidsupply line system with the liquid chamber 8. Two of said openings 22are provided in an ankle portion of the expandable last 2, one isprovided in the heel portion of the expandable last 2, two are providedin the midfoot portion of the expandable last 2, and one is provided inthe forefoot portion of the expandable last 2. A smaller or greaternumber of openings and branches, providing liquid paths to saidopenings, are possible as well.

An open-cell foam 24 is arranged around the core support element 4 inthe liquid chamber 8. The open-cell foam 24 is a flexible and softstructure that allows for the absorption and passage of liquid. In thisway, the open-cell foam may on the one hand absorb liquid and on theother hand pass liquid on towards the expandable shell 6. In theexemplary embodiment of FIG. 2 , the open-cell foam is provided in alarge portion of the liquid chamber 8. The core support element 4 formsa core/skeleton, around which the open-cell foam 24 is arranged. Theopen-cell foam 24 provides an initial shape to the expandable shell 6,while allowing for an adaptation of the shape upon receiving liquid inthe liquid chamber 8.

FIG. 3 shows an expandable last 2 in accordance with a third exemplaryembodiment of the invention in a schematic longitudinal cross-sectionalview. Various components of the expandable last 2 of FIG. 3 areidentical/similar to the components of the expandable lasts discussedabove. They are provided with corresponding reference numerals, andreference is made to their description above.

In the exemplary embodiment of FIG. 3 , the core support element 4 issubstantially T-shaped, having a substantially vertical leg and asubstantially horizontal cross-bar/cross plate, extending from thesubstantially vertical leg both towards the heel portion of theexpandable last 2 and towards the forefoot portion of the expandablelast 2. It is also possible that the core support element has twosubstantially vertical legs and a substantially horizontal crossbar/cross plate, attached to both substantially vertical legs. In thiscase, the core support element would be substantially U-shaped, inparticular in the form of an upside down U. In the exemplary embodimentof FIG. 3 , the core support element 4 is free of a liquid supply linesystem. Instead, the liquid port 16 is directly coupled to the liquidchamber 8. Liquid from the external liquid source is directly suppliedto the liquid chamber 8, without flowing through the core supportelement 4.

The expandable last 2 of FIG. 3 further comprises an expandable liquidbag 26, arranged on the outside of the expandable shell 6 at an instepportion of the expandable shell 6. The expandable last 2 of FIG. 3further comprises an ancillary liquid port 28, which is coupled to theexpandable liquid bag 26 via an ancillary liquid supply line 30. Theancillary liquid port 28 is equipped with a valve 32. The ancillaryliquid supply line 30 runs through the interior of the expandable shell6, i.e. through the liquid chamber 8. Alternatively, the ancillaryliquid supply line may run along the outside of the expandable shell 6.The ancillary liquid supply line 30 may be a flexible liquid supplyline, such as a rubber hose type liquid line.

The expandable liquid bag 26 is made from elastic material, such as fromlatex material, and may expand upon receiving liquid via the ancillaryliquid port 28 and the ancillary liquid supply line 30. The liquid port16 and the ancillary liquid port 28 allow for controlling the pressurein the liquid chamber 8 and the pressure in the expandable liquid bag 26to differ from each other, such that controlled pressure differencesbetween the instep portion of the expandable last 2 and the remainder ofthe expandable last 2 may be achieved. The liquid port 16 and theancillary liquid port 28 may be coupled to different external liquidsources. In addition/alternatively, other means for achieving a desiredpressure differential between the liquid chamber 8 and the expandableliquid bag 26, such as different valves in the liquid port 16 and theancillary liquid port 28, may also be provided.

In the exemplary embodiment of FIG. 3 , a spacer fabric 34 is arrangedin the expandable liquid bag 26. The spacer fabric 34 may provide for aninitial shape of the expandable liquid bag 26, while allowing liquid topass therethrough and distributing within the expandable liquid bag 26.

FIG. 4A shows an expandable last 2 in accordance with a fourth exemplaryembodiment of the invention in a schematic longitudinal cross-sectionalview. Various components of the expandable last 2 of FIG. 4A areidentical/similar to the components of the expandable lasts discussedabove. They are provided with corresponding reference numerals, andreference is made to their description above.

The expandable last 2 of FIG. 4A is somewhat similar to the expandablelast of FIG. 1 . The expandable last 2 of FIG. 4A also comprises asubstantially foot-shaped, form-stable core support element 4. The coresupport element 4 is somewhat shorter in a forefoot portion of theexpandable shell and has a substantially flat front end portion. Insteadof an opening towards the front of the core support element, the liquidsupply line system 20 of the core support element 4 of FIG. 4A hastransverse openings 22 close to its front end, as indicated by a circlein FIG. 4A.

The expandable last 2 of FIG. 4A further comprises an expandable liquidbag 26, arranged within the expandable shell 6 and arranged between thefront end of the core support element 4 and the toe end of theexpandable shell 6. In particular, the expandable liquid bag is arrangedto abut the front end of the core support element 4. The expandableliquid bag 26 is in liquid communication with an ancillary liquid port28 via an ancillary liquid supply line 30. In the exemplary embodimentof FIG. 4A, the ancillary liquid supply line 30 at least partly runsthrough the core support element 4. The expandable liquid bag 26 isarranged and configured to expand upon receiving liquid from an externalliquid source via the ancillary liquid port 28 and the ancillary liquidsupply line 30. Further, the expandable liquid bag 26 is arranged andconfigured to expand towards the front of the expandable last, i.e.towards the front of the expandable shell 6, as indicated in brokenlines in FIG. 4A. In particular, the expandable liquid bag 26 may expandto abut the expandable shell 6 in operation. In this way, the expandableliquid bag 26 may exert pressure onto the toe portion of the insert in aparticularly targeted manner. The liquid in the expandable liquid bag 26may exert pressure onto the toe portion in a highly reliable manner andcannot evade the toe region, irrespective of the overall circumstanceswithin the footwear. The pressure within the expandable liquid bag 26may be chosen to be the same or similar to the pressure within theliquid chamber 8 in operation. It is also possible that the pressurewithin the expandable liquid bag 26 is greater than the pressure withinthe liquid chamber 8.

FIG. 4B shows an expandable last 2 in accordance with a modification ofthe expandable last 2 of FIG. 4A. The expandable last 2 of FIG. 4B isalso in accordance with an exemplary embodiment of the invention and isalso depicted in a schematic longitudinal cross-sectional view.

In the exemplary embodiment of FIG. 4B, the core support element 4 andthe expandable liquid bag 26 in the forefoot portion of the expandableshell 6 do not abut along a flat surface, but along a contoured surface.In particular, the core support element 4 extends further to the frontof the expandable last 2 in an upper portion thereof, as compared to alower portion thereof. In this way, the expandable liquid bag isrestrained from expanding towards the top, at least to some extent, andan expansion towards the front of the expandable shell 6 is promoted.

Further, a directing element 36, such as a knitted fabric, is providedon the sole side of a front portion of the core support element 4 and onthe sole side of the expandable liquid bag 26. The directing element 36may have the double purpose of holding the sole side of the expandableliquid bag 26 in position with respect to the core support element 4 andof preventing the expandable liquid bag 26 to expand towards the soleside of the expandable shell 6. The contoured engagement surface betweenthe core support element 4 and the expandable liquid bag 26 and thedirecting element 36 may cooperate to promote the expansion of theexpandable liquid bag 26 towards the front of the expandable last 2. Theexpandable liquid bag 26 may be molded or welded to the core supportelement 4 or may be attached thereto in any other suitable manner. Also,the directing element 36 may be molded or welded to the core supportelement 4 and/or to the expandable liquid bag 26. It is also possiblethat the directing element 36 may be integrated with the expandableliquid bag 26 and/or the core support element 4. For example, theexpandable liquid bag 26 and/or the core support element may be moldedonto the directing element 36. In that case, the directing element maybe partly or fully arranged in the expandable liquid bag 26 and/or thecore support element. The directing element 36 may for example be madefrom PE, PES, or PA.

The expandable liquid bag 26 in the forefoot portion of the expandableshell 6 may be made from any suitable material that is expandable andthat can be coupled to the directing element 36. The expandable liquidbag 26 in the forefoot portion of the expandable shell 6 may be madefrom a bladder structure that has an inherent 3D shape. The expandableliquid bag may for example be made from latex or thermoplastic oradherable plastic compounds, such as Butyl.

Yet further, the expandable last comprises an expandable liquid bag 26in an upper midfoot portion of the expandable shell 6. The expandableliquid bag 26 is coupled to an external liquid source via a furtherancillary liquid port 28 and a further ancillary liquid supply line 30.The expandable liquid bag 26 in the upper midfoot portion of theexpandable shell 6 may be partly or entirely filled with a spacer fabricor may be not filled with a spacer fabric. The expandable liquid bag 26in the upper midfoot portion of the expandable shell 6 contributes tothe exertion of suitable pressure onto an instep portion of the insertvia the instep portion of the expandable shell 6.

FIG. 5 shows an expandable last 2 in accordance with a fifth exemplaryembodiment of the invention in a schematic longitudinal cross-sectionalview. Various components of the expandable last 2 of FIG. 5 areidentical/similar to the components of the expandable lasts discussedabove. They are provided with corresponding reference numerals, andreference is made to their description above.

As compared to the expandable lasts of FIGS. 1 to 4 , the expandablelast 2 of FIG. has an expansion assembly 40, which will be described indetail below. In the exemplary embodiment of FIG. 5 , the liquid port 16is directly coupled to the liquid chamber 8, such that the liquid fromthe external liquid source is directly supplied into the liquid chamber8.

The expansion assembly 40 comprises a base plate 42 and a spring-loadedpiston 44. The base plate 42 is oriented substantially horizontally andis arranged on the inside of the expandable shell 6 at a sole portionthereof. In the exemplary embodiment of FIG. 5 , the base plate 42extends over about 50% of the sole area of the expandable last 2. Thespring-loaded piston 44 is attached to the base plate 42 and is alsooriented substantially horizontally. The spring-loaded piston isarranged to stretch the expandable shell 6 in a longitudinal directionof the expandable last 2 and to exert localized pressure onto theexpandable shell 6 in a heel portion and toe portion of the expandablelast 2. With the localized pressure stemming from the spring of thespring-loaded piston 44, no active means, i.e. no means relying on anexternal supply of energy, are required for exerting the localizedpressure. The localized pressure is solely generated by the spring ofthe spring-loaded piston 44, acting against its compression.

The expansion assembly 40 further comprises a mounting rod 54, which iscoupled to the lid 10. Via the mounting rod 54, the expansion assembly40 is fixed in position with respect to the lid 10. An overall stablearrangement may be achieved, and the expansion assembly may provide coresupport to the expandable last 2, similar to the core support element 4described above.

The expandable last 2 of FIG. 5 allows for providing localized pressureat selected portions of the expandable last 2, while providing a moreuniform all around pressure via the liquid in the liquid chamber 8. Inthis way, different pressure levels and/or a dynamic application ofdifferent pressures at different times may be achieved in an effectivemanner.

FIG. 6 shows an expandable last 2 in accordance with a sixth exemplaryembodiment of the invention in a schematic longitudinal cross-sectionalview. Various components of the expandable last 2 of FIG. 6 areidentical/similar to the components of the expandable lasts discussedabove. They are provided with corresponding reference numerals, andreference is made to their description above.

The expandable last 2 of FIG. 6 is somewhat similar to the expandablelast 2 of FIG. 5 . However, the expansion assembly 40 differsconsiderably from the expansion assembly 40 from FIG. 5 . In particular,instead of the spring-loaded piston 44, an active piston 46 is provided.In the exemplary embodiment of FIG. 6 , the active piston 46 is apneumatically operated piston 46. Similar to the spring-loaded piston 44of FIG. 5 , the pneumatically operated piston 46 exerts localizedpressure onto the heel portion and the toe portion of the expandableshell 6.

The expansion assembly 40 comprises a pneumatic port 48 in the lid 10and a pneumatic line 50, connecting the pneumatic port 48 and thepneumatically operated piston 46. The pneumatic port 48 has a valve 52.In operation, the extension of the pneumatically operated piston 46 canbe controlled via the pneumatic pressure therein, which in turn may becontrolled via an external gas source, such as an external air source,coupled to the pneumatic port 48. In this way, the exertion of localizedpressure can be controlled with a high degree of granularity.

The expansion assembly 40 of FIG. 6 also comprises a mounting rod 54.Via the mounting rod 54, the base plate 42 and the pneumaticallyoperated piston 46 are fixed in position with respect to the lid 10. Inthis way, the expansion assembly 40 has high positional stability withinthe expandable last 2, and the expandable last 2 can be handledconveniently as an overall highly stable structure.

FIG. 7 shows an expandable last 2 in accordance with a seventh exemplaryembodiment of the invention in a schematic longitudinal cross-sectionalview. Various components of the expandable last 2 of FIG. 7 areidentical/similar to the components of the expandable lasts discussedabove. They are provided with corresponding reference numerals, andreference is made to their description above.

The expandable last 2 of FIG. 7 is somewhat similar to the expandablelast 2 of FIG. 5 , albeit with some significant differences. Theexpandable last 2 of FIG. 7 also has an expansion assembly 40, whichcomprises a base plate 42 and a spring-loaded piston 44. The expansionassembly 40 further comprises a mounting rod 54, which is mounted to thelid 10 and to which the base plate 42 is mounted. The spring-loadedpiston 44 is in turn mounted to the base plate 42. In this way, thespring-loaded piston 44, the base plate 42, the mounting rod 54, and thelid 10 are fixed in position with respect to each other. In thisarrangement, the spring-loaded piston 44 exerts localized pressure ontothe expandable shell 6 at a single portion thereof. In the exemplaryembodiment of FIG. 7 , the spring-loaded piston 44 exerts localizedpressure onto the toe portion of the expandable shell 6.

The expandable last 2 of FIG. 7 further comprises a heater 60. In theexemplary embodiment of FIG. 7 , the heater 60 is embodied as anelectric heater. In particular, the heater is embodied as a heating coilthat is wound around the mounting rod 54. The heater 60 is coupled to apower supply cable 62 that runs through the lid 16 and that may becoupled to an external power source, such as a power adapter that is inturn connectable to a standard power outlet. Via the heater, the liquidin the liquid chamber 8 may be heated and expanded. The expansion of theliquid may be used for the expansion of the expandable shell 6. In thisway, in addition to the localized pressure exerted by the expansionassembly 40, a highly uniform pressure may be generated all around theexpandable shell 6.

In the exemplary embodiment of FIG. 7 , both the lid 10 as well as theexpandable shell 6 are free of a liquid port. When being arranged withinthe footwear and exerting pressure onto the insert towards the inside ofthe footwear, no liquid is added or evacuated from the liquid chamber 8.The heating of the liquid within the liquid chamber 8 provides for theall around exertion of pressure onto the insert. It is pointed out thatany suitable liquid may be used for achieving the expansion of theexpandable shell 6. For example, the liquid chamber 8 may be filled withwater, and the expansion of the water upon heating may provide for thedesired increase in pressure.

It is pointed out that, instead of/in addition to a heater beingprovided in the liquid chamber 8, the expandable last may be placed intoa heating device, such as an electric oven or a microwave oven, and maythen be inserted into the footwear. This heating may also achieve theexpansion of the liquid in the liquid chamber 8, and the exertion ofpressure onto the insert via the expandable shell 6 may take place viathe heated liquid.

FIG. 8 shows an expandable last 2 in accordance with an eighth exemplaryembodiment of the invention in a schematic longitudinal cross-sectionalview. Various components of the expandable last 2 of FIG. 8 areidentical/similar to the components of the expandable lasts discussedabove. They are provided with corresponding reference numerals, andreference is made to their description above.

The expandable last 2 of FIG. 8 is somewhat similar to the expandablelast 2 of FIG. 5 , albeit with some significant differences. Theexpandable last 2 of FIG. 8 does not have a core support element nor anexpansion assembly nor a heater, as described with respect to FIGS. 1 to7 . However, the expandable last 2 of FIG. 8 has a liquid port 16,running through the lid 10, for inserting liquid into the liquid chamber8. The expandable shell 6 expands solely in response to the introductionof liquid into the liquid chamber 8.

The expandable shell 6 has dimension-specific elastic properties. In theexemplary embodiment of FIG. 8 , a midfoot portion 70 of the expandableshell 6 has dimension-specific elastic properties. It is possible thatother portions of the expandable shell 6 have dimension-specific elasticproperties as well.

In particular, the midfoot portion 70 of the expandable shell 6stretches in a longitudinal dimension 72 at a lower liquid pressure thanin a circumferential dimension 74. In this context, the circumferentialdimension 74 is defined as extending around the tube-like cross-sectionof the midfoot portion 70. With the expandable shell 6 thus expandingeasier in the longitudinal dimension 72 than in the circumferentialdimension 74 in the midfoot portion 70, an increase in liquid pressureleads to an elongation of the midfoot portion 70 along the length of theexpandable last 2, before a circumferential expansion and, thus, anincrease in cross-section in the midfoot portion 70 takes place. In thisway, the expandable last 2 may first adapt to a particular footwearsize/length, before exerting a highly uniform all around pressure ontothe insert against the inside of the footwear. In a particular exemplaryembodiment, the length of the midfoot portion may extend by between 10%and 30%, in particular by about 20%, before the circumferentialexpansion takes place.

FIG. 9 shows an expandable last 2 in accordance with a ninth exemplaryembodiment of the invention in a schematic longitudinal cross-sectionalview. Various components of the expandable last 2 of FIG. 9 areidentical/similar to the components of the expandable lasts discussedabove. They are provided with corresponding reference numerals, andreference is made to their description above.

The expandable last 2 of FIG. 9 comprises a rigid forefoot and insteplast portion 80 and a rigid heel last portion 82. The rigid forefoot andinstep last portion 80 and the rigid heel last portion 82 are made fromaluminum. Jointly, they form a split last, having a rigid front portionand rigid rear portion. Both the rigid forefoot and instep last portion80 and the rigid heel last portion 82 are heatable. They are coupledwith a front power supply line 81 and a read power supply line 83,respectively, via which internal heaters of the rigid forefoot andinstep last portion 80 and the rigid heel last portion 82 may beprovided with electric energy. The internal heaters may be inductionheaters or may comprise heating cartridges or may comprise othersuitable heating devices. It is also possible that the rigid forefootand instep last portion 80 and the rigid heel last portion 82 are notheatable. They may still be thermally conductive, and the lines 81, 83may be sensor lines, coupling temperature sensors within the rigidforefoot and instep last portion 80 and the rigid heel last portion 82to a control unit.

The rigid forefoot and instep last portion 80 and the rigid heel lastportion 82 are movable with respect to each other. The expandable last 2comprises a pneumatic actuator 84, which is configured to control aspacing between the rigid forefoot and instep last portion 80 and therigid heel last portion 82. The expandable last 2 further comprises afirst gas port 86, equipped with a valve 88, and a second gas port 90,equipped with a valve 92. The first gas port 86 and the second gas port88 are coupled to the pneumatic actuator 84 via a first gas line 94 anda second gas line 96, respectively. The first gas port 86 and the secondgas port 90 are configured to introduce gas into the pneumatic actuator84 from an external gas source and to release gas from the pneumaticactuator 84, respectively. By an according control of the first gas port86 and the second gas port 90, the pressure in the pneumatic actuator 84and, thus, the spacing between the rigid forefoot and instep lastportion 80 and the rigid heel last portion 82 may be controlled in ahighly accurate manner. The split last may thus be adapted to differentfootwear sizes/lengths over a wide size/length range.

The expandable last 2 further comprises an expandable shell 6, which hasa liquid chamber 8 therein. The expandable last 2 further comprises aliquid port 16, having a valve 18, which is coupled to the liquidchamber 8 via a liquid supply line 20. In operation, liquid may bereceived in the liquid chamber 8, and the expandable shell 6 may exert ahighly uniform pressure onto an insert on the inside of the footwear inthose portions of the footwear that are between the rigid forefoot andinstep last portion 80 and the rigid heel last portion 82.

The expandable last 2 further comprises an expandable liquid bag 26,arranged around the toe portion of the rigid forefoot and instep lastportion 80. The liquid chamber 8 and the expandable liquid bag 26 arecoupled via an ancillary liquid supply line 30. The ancillary liquidsupply line 30 extends through the rigid forefoot and instep lastportion 80. With the expandable liquid bag 26, the pressure exerted ontothe insert in a forefoot portion of the footwear may be made moreuniform than with the rigid forefoot and instep last portion 80. Theexpandable liquid bag may balance out sharp contours of the inside ofthe footwear in the toe portion in a particularly effective manner.

With the combination of the rigid forefoot and instep last portion 80and the rigid heel last portion 82 on the one hand and the expandableshell 6 and the expandable liquid bag 26 on the other hand, a goodcompromise between using rigid, comparably straightforward to implementlast portions and using expandable last portions, which are highlyflexible and well-suited for applying a uniform pressure, may beachieved.

FIG. 10 illustrates a method for furnishing footwear 110 with an insert100 in accordance with an exemplary embodiment of the invention. Themethod makes use of an expandable last 2 in accordance with an exemplaryembodiment of the invention. In the exemplary illustration of FIG. 10 ,the expandable last 2 corresponds to the expandable last 2 of FIG. 5 .However, it is stressed that an expandable last in accordance with anyof the embodiments, as described herein, may be used.

FIG. 10A depicts the expandable last 2 and an insert 100. The insert 100is arranged over the expandable last 2. The insert 100 is in a relaxedstate, i.e. in a state unstretched by the expandable last 2. In theillustration of FIG. 10 , the insert 100 is a waterproof, breathablebootie. Accordingly, the method illustrated in FIG. is a method forwaterproofing footwear. The waterproof, breathable bootie may forexample be embodied in accordance with any of the embodiments, asdescribed in PCT/EP2017/068030 and/or PCT/EP2018/084179.

The insert 100 comprises a first glue-covered area 102 around the toeportion of the insert 100, a second glue-covered area 104 around theheel portion of the insert 100, and a third glue-covered area 106 alongthe collar of the insert 100. In the exemplary embodiment of FIG. 10 ,all of the first glue-covered area 102, the second glue-covered area104, and the third glue-covered area are provided with heat-activatedadhesive. Instead of/in addition to the third glue-covered area 106, atextile tape, sewn to the insert 100 and provided with suitableadhesive, may be provided.

FIG. 10B depicts the expandable last 2 and the insert 100 inserted intothe interior of the footwear 110. In the illustrated embodiment of FIG.10 , the footwear 110 is a low shoe. When introducing the expandablelast, the insert 100 is placed onto the sole portion of the interior ofthe footwear 110 and against the heel portion of the interior of thefootwear 110. With the expandable last 2 being in an unexpanded stateand the insert 100 being in a relaxed state, the insert 100 is spacedfrom the other portions of the inside of the footwear 110.

FIG. 10C depicts the expandable last 2 with the spring-loaded piston 44having a larger horizontal extension than in FIG. 10B. The change inextension is the result of the spring of the spring-loaded pistoncounter-acting its compression and exerting localized pressure onto thetoe portion and the heel portion of the expandable shell 6. The changein extension may be triggered by a release mechanism. For example, thespring-loaded piston may have a release button, which may beoperated/pushed by an operator. For example, the release button may beoperated manually, either through the footwear 110, the insert 100 andthe expandable shell 6 or through the expandable shell 6 only or via asuitable mechanism at the lid 10. It is also possible that thespring-loaded piston expands without a release mechanism. For example,the spring-loaded piston may continuously force its extension, whenbeing inserted into the footwear, similar to a shoe tree. It is furtherpossible that the introduction of liquid causes the spring-loaded pistonto expand or that the change in extension is triggered in any othersuitable manner.

FIG. 10D depicts the expandable last 2 with an external liquid supplyline 120 coupled to the liquid port 16 of the expandable last 2. Via theliquid port 16, water is introduced into the liquid chamber 8 of theexpandable last 2. In the exemplary embodiment of FIG. 10 , the water isintroduced into the liquid chamber 8 with a temperature of between 60°C. and 98° C., in particular with a temperature of about 95° C. Also,water is introduced until a target liquid pressure is reached in theliquid chamber 8. The target liquid pressure may be between 0.1 bar and2 bar, in particular about 0.2 bar. As a result, the insert 100 ispressed against the inside of the footwear 110. The water provides for auniform pressure within the liquid chamber 8 and presses the insert 100towards the inside of the footwear 110 in a highly uniform manner. Thetemperature of the water also activates the heat-activated adhesive inthe first, second, and third glue-covered areas 102, 104, 106. It isunderstood that the temperature and pressure of the liquid may beselected, depending on the particular liquid used. Various types ofheat-activated adhesives may be activated at temperatures between 60° C.and 200° C., and the liquid may be introduced at a temperature suitablefor the adhesive in question. An example for a suitable adhesive istemperature re-activatable PU, such as Irotex from P. B. Fuller.

FIG. 10E depicts the expandable last 2 with the external liquid supplyline 120 decoupled from the liquid port 16.

FIG. 10F additionally depicts a toe cap protector 130, put over the toeportion of the footwear 110. The toe cap protector 130 may be held inplace by a rubber band, being wrapped around the heel of the footwear110. In this way, a counter-pressure may be provided at the toe portionof the footwear 110 and the toe portion of the footwear 110 may beprotected.

FIG. 10G depicts the expandable last 2, the insert 100, the footwear110, and the toe cap protector 130 loosely placed in a bag 138. The bag138 in turn is placed in a pressure chamber 140. The pressure chamber140 is coupled to a pressure line 142, through which pressurized air canflow into the pressure chamber 140.

FIG. 10H depicts the situation, after pressurized air has flown into thepressure chamber 140. In the exemplary embodiment of FIG. 10 , an airpressure of between 2 bar and 7 bar, in particular an air pressure ofabout 5.5 bar, is used for pressurizing the pressure chamber 142. Thepressurized air presses the bag 138 against the footwear 110 andprovides for a counter-pressure against the expandable last 2.

The combination of water pressure in the expandable last 2, heat fromthe water in the expandable last 2, and air pressure in the pressurechamber 140 are a highly effective way for adhering the insert 100 tothe inside of the footwear 110. A very stable attachment with a highlyuniform adhesion across the first, second, and third glue-covered areas102, 104, 106 may be achieved.

FIG. 11 shows an expandable last 2 in accordance with a tenth exemplaryembodiment of the invention of a schematic longitudinal cross-sectionalview. Various components of the expandable last 2 of FIG. 11 areidentical/similar to the components of the expandable lasts discussedabove. They are provided with corresponding reference numerals, andreference is made to their description above.

The expandable last 2 of FIG. 11 is somewhat similar to the expandablelast 2 of FIG. 5 . In particular, the expandable last 2 of FIG. 11 alsohas an expansion assembly and also has a liquid port 16 that is directlycoupled to the liquid chamber 8. However, the expansion assembly 40 ofthe expandable last 2 of FIG. 11 is quite different from the expansionassembly 40 of the expandable last 2 of FIG. 5 , as will be laid outbelow.

The expansion assembly 40 of the expandable last 2 of FIG. 11 has aform-stable core support element 4. The core support element 4 issubstantially T-shaped. In particular, the core support element 4 hasthe design of the core support element 4 described above with respect toFIG. 3 . Instead of being viewed as a T-shaped core support element, thecore support element 4 may also be seen as the combination of a baseplate and a mounting rod, attaching the base plate to the lid 10, asdescribed above with respect to FIG. 5 . The properties described abovewith respect to various embodiments of the core support element anddescribed above with respect to various embodiments of the combinationof the base plate and the mounting rod may be implemented in theframework of the expansion assembly of the expandable last 2 of FIG. 11in an analogous manner.

In the exemplary embodiment of FIG. 11 , the expansion assembly 40comprises a spring skeleton 55. The spring skeleton 55 is fixed to thelid 10 and extends towards a forefoot portion of the expandable last 2and towards a heel portion of the expandable last 2 from the lid 10. Inparticular, the spring skeleton 55 has a forefoot spring portion 56 anda heel spring portion 57. Both the forefoot spring portion 56 and theheel spring portion 57 are configured to exert localized pressure ontothe expandable shell 6 of the expandable last 2.

The forefoot spring portion 56 has a waved shape. In particular, theforefoot spring portion 56 has a first exposed portion 56 a and a secondexposed portion 56 b. The first exposed portion 56 a is located at aninstep portion of the expandable last 2. The second exposed portion 56 bis located at a toe portion of the expandable last 2. The first andsecond exposed portion 56 a, 56 b may be thought of as high portions ofthe waved shape of the forefoot spring portion 56, when fitting astraight line through the waved shape of the forefoot spring portion 56.

The forefoot spring portion 56 further comprises a pressure exertion pad56 c. The pressure exertion pad 56 c is arranged at the forefoot endportion of the forefoot spring portion 56.

The heel spring portion 57 extends from the lid 10 towards a heelportion of the expandable last 2. The heel spring portion 57 has apressure exertion pad 57 a at the heel end portion of the heel springportion 57.

The forefoot spring portion 56 and the heel spring portion 57 are of ametal strip design. In the longitudinal direction of the expandable last2, the forefoot spring portion 56 has the described waved shape from thelid 10 to the toe portion of the expandable last 2, and the heel springportion 57 has the depicted curved shape from the lid 10 to the heelportion of the expandable last 2. In the transverse direction of theexpandable last 2, i.e. in the direction orthogonal to the viewing planeof FIG. 11 , both the forefoot spring portion 56 and the heel springportion 57 have a substantially constant width, thus forming a metalstrip between the toe portion of the expandable last 2 and the heelportion of the expandable last 2. The forefoot spring portion 56 and theheel spring portion 57 may in particular be made of a metal strip havinga width between 1 cm and 3 cm, in particular a width of between 1 cm and2 cm.

In the exemplary embodiment of FIG. 11 , the forefoot spring portion 56and the heel spring portion 57 are made from a continuous metal strip,i.e. they are provided as an integrated one-piece structure. However, itis also possible that the forefoot spring portion 56 and the heel springportion 57 are separate elements, with each of these separate elementsbeing mounted to the lid 10 or to the core support element 4.

An exception to the constant width of the forefoot spring portion 56 andthe heel spring portion 57 are the pressure exertion pad 56 c at the toeportion of the forefoot spring portion 56 and the pressure exertion pad57 a the heel portion of the heel spring portion 57. The pressureexertion pads 56 c, 57 a have a wider extension than the forefoot springportion 56 and the heel spring portion 57, thus providing for a somewhatmore extended application of pressure onto the expandable shell 6.

The spring action of the spring skeleton 55 is described as follows.Both the forefoot spring portion 56 and the heel spring portion 57 areconfigured to exert a spring force that pushes the forefoot springportion 56 and the heel spring portion 57 upwards in the expandable last2.

In this context, the term upwards corresponds to the upwards directionin the viewing plane of FIG. 11 , which also corresponds to the upwardsdirection of the footwear, when oriented in the normal use position.This upwards directed spring force is illustrated in FIG. 11 by thespring skeleton 55 being shown in two different positions/states. Inparticular, the spring skeleton 55 is on the one hand shown in phantom,with said position/state representing a potential positon/state directlyafter insertion of the expandable last 2 into a footwear. In thisposition/state, the forefoot spring portion 56 and the heel springportion 57 are biased downwards, and the forefoot spring portion 56 andthe heel spring portion 57 exert an upwards directed force. This upwardsdirected force pushes/forces the spring skeleton 55 in the seconddepicted position/state, being shown in solid lines. In thispositon/state, the first exposed portion 56 a exerts localized pressureonto the instep portion of the expandable shell 6, the second exposedportion 56 b exerts localized pressure onto the toe portion of theexpandable shell 6, and the heel end portion of the heel spring portion57 exerts localized pressure onto the heel portion of the expandableshell 6. The first exposed portion 56 a, which is roughly in the middlebetween the lid 10 and the toe end portion of the forefoot springportion 56, exerts localized pressure in a substantially upwarddirection. The second exposed portion 56 b which is a toe end portion ofthe forefoot spring portion 56, exerts localized pressure in a forwardand upward direction. The heel end portion of the heel spring portion 57exerts localized pressure in a rearward and upward direction.

With the spring skeleton 55 of the expandable last 2 of FIG. 11 ,localized pressure may be exerted at particularly crucial portions,namely at the instep portion, the toe portion and the heel portion, withthe particular directions of pressure being particularly effective forthe attachment of the insert. The expansion assembly 40 of theexpandable last 2 of FIG. 11 co-operates very well with the more uniformapplication of pressure via liquid introduced into the expandable shell6 via the liquid port 16.

It has been described that the spring skeleton 55 and the core supportelement 4 are jointly viewed as an expansion assembly. However, one canalso view the spring skeleton 55 as an additional element thatsupplements the core support element 4. In particular, the core supportelement 4 may be embodied in any of the variations described above withrespect to FIGS. 1 to 4 , and the spring skeleton may be added theretofor exertion of localized pressure.

FIG. 12 shows an expandable last 2 in accordance with an eleventhexemplary embodiment of the invention in a schematic longitudinalcross-sectional view. Various components of the expandable last 2 ofFIG. 12 are identical/similar to the components of the expendable lastdiscussed above. They are provided with corresponding referencenumerals, and reference is made to their description above.

The expandable last 2 of FIG. 12 is somewhat similar to the expandablelast 2 of FIG. 11 . In particular, the expandable last 2 of FIG. 12 alsocomprises an expansion assembly 40 that has a spring skeleton 55. In theexemplary embodiment of FIG. 12 , the expandable last 40 does not have acore support element. However, the expandable last 40 of FIG. 12 may beadditionally provided with a core support element, as described herein.

The spring skeleton 55 of the expandable last 2 of FIG. 12 also has aforefoot spring portion 56 and a heel spring portion 57. The heel springportion 57 is embodied in the same manner as the heel spring portion 57of the spring skeleton 55 of FIG. 11 . Reference is made to itsdescription above.

In the exemplary embodiment of FIG. 12 , the forefoot spring portion 56is substantially L-shaped from the lid 10 to its toe end portion. Thissubstantially L-shaped structure may be ridged, as depicted in FIG. 12 ,or may exert an upwards spring force, as described with respect to theforefoot spring portion 56 of FIG. 11 . The forefoot spring portion 56of FIG. 12 comprises an instep spring element 58 that extends along theinstep portion of the expandable shell 6. In particular, the instepspring element 58 extends from close to the toe portion of the describedsubstantially L-shaped structure in an upward and rearward direction.The terms upward and rearward refer to the depicted orientation of FIG.12 , which corresponds to the orientation of the expandable last 2 wheninserted into a footwear in its normal use orientation. It can also besaid that the instep spring element 58 has its free end pointing in arearward and upward direction.

The instep spring element 58 is configured to exert localized pressureonto the instep portion of the expandable shell 6. For illustration, theinstep spring element 58 is shown in two states/positions. On the onehand, the instep spring element 58 is shown in phantom, which maycorrespond to a positon/state directly after insertion of the expandablelast 2 into the footwear. When in said positon/state, a spring action ofthe instep spring element 58 forces the instep spring element 58upwards. This spring action leads to the instep spring element 58 beingforced upwards and exerting localized pressure onto the instep portionof the expandable shell 6. Said pressure exertion position/state isshown in a solid line in FIG. 12 .

The expandable last 2 of FIG. 12 has similar properties as theexpandable last 2 of FIG. 11 . In particular, both rely on a springskeleton 55 for exerting localized pressure. While both expandable lastsmay be provided with a core support element or not, the substantiallyrigid L-shape of the forefoot spring element 56 of the expandable last 2of FIG. 12 provides more inherent support to the spring skeleton 55,thus making it easier to provide the expansion assembly 40 without thecore support element.

FIG. 13 shows an expandable last 2 in accordance with a twelfthexemplary embodiment of the invention in a longitudinal cross-sectionalview. Various components of the expandable last 2 of FIG. 13 areidentical/similar to the components of the expandable lasts discussedabove. They are provided with corresponding reference numerals, andreference is made to their description above.

The expandable last 2 of FIG. 13 has an expandable shell 6, mounted to alid 10. For the description of the expandable shell 6 and the lid 10,reference is made to the description of the expandable lasts discussedabove.

Within the expandable shell 6, a granulate chamber 61 is provided. Agranulate port 62 is provided in the lid 10. The granulate port 62 formsa granulate channel into the granulate chamber 61. Via the granulateport 62, granulate 63 may be introduced into the expandable shell 6 andmay be sucked out of the expandable shell 6. For illustrative purposes,a small amount of granulate 63 is shown within the granulate chamber 61in FIG. 13 . In the exemplary embodiment of FIG. 13 , the granulate 63is provided in the form of metal or glass balls, in particular metal orglass balls having a diameter of between 2 mm and 8 mm, further inparticular having a diameter of between 3 mm and 6 mm. The metal may besteel. It is also possible that the granulate is provided in the form ofsand.

The granulate 63 that is introduced into the granulate chamber 61 may beprovided by an external granulate source 64. The external granulatesource 64 has a granulate container 65 and a granulate heater 67. Thegranulate container 65 is coupled to the granulate port 62 with agranulate dosing valve 66, being interposed between the granulatecontainer 65 and the granulate port 62. Via the granulate heater 67 andthe granulate dosing valve 66, the amount and temperature of thegranulate 63 within the expandable shell 6 of the expandable last 2 maybe controlled.

In operation, the granulate 63 may provide for a substantially uniformpressure onto the insert for pressing the same against the footwear.Also, with the granulate 63 being heated, the granulate 63 is aneffective means for activating a heat-activated adhesive, which may beused for attaching the insert to the footwear. As described above, theexpandable shell 6 may have, at least in one or more regions thereof,dimension-specific elastic properties. Also, as described above, aform-stable core support element or an expansion assembly may bearranged within the expandable shell 6. In this way, localized exertionof pressure may be combined with the more uniform exertion of pressure,as achieved via the granulate 63.

The expandable shell 6 of the expandable last 2 of FIG. 13 may be madefrom latex material, as described above with respect to various otherembodiments of the expandable last. It is also possible that theexpandable shell 6 of the expandable last 2 of FIG. 13 is made ofsynthetic material, in particular of a textile material. The expandableshell 6 may for example by a nylon sock.

Test Methods and Definitions

The waterproofness of footwear may be determined by use of theCentrifuge test described in U.S. Pat. No. 5,329,807, and incorporatedby reference herein in its entirety. The centrifuge tests may be carriedout for 30 minutes. The footwear article is considered to be waterproofif no leakage is seen after 30 minutes.

The breathability of footwear may be assessed in accordance with thedetermination of the Whole Boot Moisture Vapor Transmission Rate Test inaccordance with the Department of Defense Army Combat Boot TemperateWeather Specifications. The specifications are as follows:

Whole Boot Breathability

The boot breathability test shall be designed to indicate the MoistureVapor Transmission Rate (MVTR) through the test sample by means of adifference in concentration of moisture vapor between the interior andthe exterior environment.

Apparatus

-   -   a. The external test environment control system shall be capable        of maintaining 23 (±1) ° C. and 50%±2% relative humidity        throughout the test duration.    -   b. The weight scale shall be capable of determining the weight        of test samples filled with water to an accuracy of (±0.01)        gram.    -   c. The water holding bag shall be flexible so that it can be        inserted into the test sample and conform to the interior        contours; it must be thin enough so that folds do not create air        gaps; it must have much higher MVTR than the footwear product to        be tested; and it must be waterproof so that only moisture vapor        contacts the interior of the footwear product rather than liquid        water.    -   d. The internal heater for the test sample shall be capable of        controlling the temperature of the liquid water uniformly in the        test sample to 35 (±1) ° C.    -   e. The sealing method around the collar of the test sample shall        be impervious to both liquid water and water vapor.

Procedure

-   -   a. Place sample in test environment and condition for at least        12 hours.    -   b. The heating device is inserted into the water holding bag and        the complete assembly is then placed into the test sample        opening and filled with water to a height of 5 cm measured from        inside sole.    -   c. Seal opening around the collar with plastic wrap around the        top of the footwear and tape over using packaging tape.    -   d. Heat water in test sample to 35° C.    -   e. Weigh test sample and record as Wi.    -   f. Hold temperature in test sample after weighing for a minimum        of 4 hours.    -   g. After a minimum of 4 hours, reweigh test sample. Record        weight as Wf and test duration as Td.    -   h. Calculate MVTR of the test sample in grams/hour from the        equation below:

MVTR=(Wi−Wf)/Td.

This test is in accordance with ASTM D8041 (2016).

For example, for a low ankle shoe of European shoe size 42, the footwearmay be considered breathable if above calculated value is above 1.5grams/hour. For larger/smaller shoe sizes, said limit value may beextrapolated in accordance with the increased/decreased surface area ofthe shoe.

The waterproofness and the breathability of the bootie as a whole mayalso be determined by use of the Centrifuge test and the Whole BootMoisture Vapor Transmission Rate Test, respectively, as laid out above.

While the invention has been described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed, but that theinvention will include all embodiments falling within the scope of theappended claims.

1. Expandable last (2) for furnishing footwear (110) with an insert(100), comprising: an expansion assembly (40); an expandable shell (6),arranged around the expansion assembly (40); and a liquid chamber (8)within the expandable shell (6); wherein the expandable last (2) isinsertable into the footwear (110) through a collar of the footwear(110) and wherein the expandable shell (6) is configured to expand forpressing the insert (100) towards an inside of the footwear (110); andwherein the expansion assembly (40) is configured to adapt its extensionfor exerting localized pressure onto the expandable shell (6) towardsthe inside of the footwear (110).
 2. Expandable last (2) according toclaim 1, wherein the expansion assembly (40) comprises at least one of ahydraulically operated piston, a pneumatically operated piston (46), anelectrically operated piston, and a spring-loaded piston (44) forexerting the localized pressure.
 3. Expandable last (2) according toclaim 2, wherein the expansion assembly (40) comprises a base plate(42), to which said at least one of a hydraulically operated piston, apneumatically operated piston (46), an electrically operated piston, anda spring-loaded piston (44) is mounted.
 4. Expandable last (2) accordingto any of claims 1 to 3, wherein the expansion assembly (40) comprises aspring-loaded piston (44) for exerting the localized pressure, whereinthe spring-loaded piston (44) comprises at least one of a coil springand a gas spring.
 5. Expandable last (2) according to any of claims 1 to4, wherein the expansion assembly (40) is configured to exert localizedpressure onto at least one of a toe portion and a heel portion of theexpandable shell (6).
 6. Expandable last (2) according to claim 1,wherein the expansion assembly (40) comprises a spring skeleton (55)having a forefoot spring portion (56), configured to exert localizedpressure onto at least one of a toe portion and an instep portion of theexpandable shell (6), and having a heel spring portion (57), configuredto exert localized pressure onto a heel portion of the expandable shell(6).
 7. Expandable last (2) according to claim 6, wherein the forefootspring portion (56) is configured to force its forefoot end portion in aforward and upward direction.
 8. Expandable last (2) according to claim6 or 7, wherein the forefoot spring portion (56) has a waved shape, witha first exposed portion (56 a) exerting localized pressure onto theinstep portion of the expandable shell (6) and with a second exposedportion (56 b) exerting localized pressure onto the toe portion of theexpandable shell (6).
 9. Expandable last (2) according to claim 6 or 7,wherein the forefoot spring portion (56) comprises an instep springelement (58), extending along the instep portion of the expandable shell(6) and having its free end pointing rearwards.
 10. Expandable last (2)according to any of claims 6 to 9, wherein the heel spring portion (57)is configured to force its heel end portion in a rearward and upwarddirection.
 11. Expandable last (2) according to any of claims 6 to 10,wherein the expansion assembly (40) comprises a form-stable core supportelement (4), wherein the form-stable core support element (4) is inparticular substantially L-shaped or substantially T-shaped. 12.Expandable last (2) according to any of claims 1 to 11, furthercomprising a lid (10), to which the expandable shell (6) is mounted. 13.Expandable last (2) according to claim 12, wherein the expansionassembly (40) is fixed in position with respect to the lid (10), inparticular mounted to the lid (10) via a mounting rod (54). 14.Expandable last (2) according to any of claims 1 to 13, wherein theexpansion assembly (40) is attached to the expandable shell (6). 15.Expandable last (2) according to any of claims 1 to 14, furthercomprising a liquid port (16), providing liquid communication betweenthe liquid chamber (8) and an external liquid source (120), wherein theexpandable shell (6) is configured to expand for pressing the insert(100) towards an inside of the footwear (110), when receiving liquid inthe liquid chamber (8) via the liquid port (16).
 16. Expandable last (2)according to any of claims 1 to 14, further comprising a heater (60)arranged in the liquid chamber (8), wherein the heater (60) isconfigured to heat liquid in the liquid chamber (8) for expanding theexpandable shell (6) and pressing the insert (100) towards an inside ofthe footwear (110) via an increase in volume of the liquid in the liquidchamber (8).
 17. Expandable last (2) according to claim 16, wherein theheater (60) is an electric heater.
 18. Expandable last (2) according toclaim 16 or 17, wherein the expansion assembly (40) and the heater (60)are fixed in position with respect to each other, wherein the expansionassembly (40) and the heater (60) are in particular formed as anintegrated structural unit.
 19. Expandable last (2) according to any ofclaims 16 to 18, further comprising a lid (10), to which the expandableshell (6) is mounted.
 20. Expandable last (2) according to claim 19,wherein the expandable shell (6) and the lid (10) form a liquid-tightenclosure.
 21. Expandable last (2) for furnishing footwear (110) with aninsert (100), comprising: a form-stable core support element (4); anexpandable shell (6), arranged around the core support element (4); aliquid chamber (8) within the expandable shell (6); and a liquid port(16), providing liquid communication between the liquid chamber (8) andan external liquid source (120); wherein the expandable last (2) isinsertable into the footwear (110) through a collar of the footwear(110) and wherein, when receiving liquid in the liquid chamber (8) viathe liquid port (16), the expandable shell (6) is configured to expandfor pressing the insert (100) towards an inside of the footwear (110).22. Expandable last (2) according to claim 21, wherein the core supportelement (4) is substantially L-shaped or substantially T-shaped orsubstantially U-shaped or substantially foot-shaped.
 23. Expandable last(2) according to claim 21 or 22, wherein the core support element (4) isrigid, in particular made from metal or rigid plastics material. 24.Expandable last (2) according to claim 21 or 22, wherein the coresupport element (4) is flexible, in particular made from resilientrubber material.
 25. Expandable last (2) according to any of claims 21to 24, wherein the liquid chamber (8) comprises substantially the entirevolume between the core support element (4) and the expandable shell(6).
 26. Expandable last (2) according to any of claims 21 to 25,wherein the core support element (4) comprises at least one liquidsupply line (20), coupled to the liquid port (16) and providing liquidcommunication between the liquid port (16) and the liquid chamber (8).27. Expandable last (2) according to claim 26, wherein the at least oneliquid supply line (20) is arranged within the core support element (4)and has at least one opening (22) towards the liquid chamber (8). 28.Expandable last (2) according to any of claims 21 to 27, wherein theexpandable shell (6) is elastic, in particular made from latex material.29. Expandable last (2) according to any of claims 21 to 28, wherein theexpandable shell (6) has, at least in one or more regions thereof,dimension-specific elastic properties.
 30. Expandable last (2) accordingto any of claims 21 to 29, wherein the liquid chamber (8) is at leastpartly filled with an open-cell foam (24), in particular with anopen-cell polyurethane foam, and/or with a spacer fabric.
 31. Expandablelast (2) according to any of claims 21 to 30, further comprising atleast one expandable liquid bag (26), arranged outside or inside of theexpandable shell (6).
 32. Expandable last (2) according to claim 31,further comprising at least one ancillary liquid port (28), providingliquid communication between the at least one expandable liquid bag (26)and at least one external liquid source.
 33. Expandable last (2)according to claim 32, further comprising at least one ancillary liquidsupply line (30), coupling the at least one expandable liquid bag (26)to the at least one ancillary liquid port (28), wherein the at least oneancillary liquid supply line (30) in particular runs through the liquidchamber (8).
 34. Expandable last (2) according to any of claims 31 to33, wherein the at least one expandable liquid bag (26) comprises atleast one of: an expandable liquid bag at an instep portion of theexpandable shell (6); an expandable liquid bag at a toe portion of theexpandable shell (6); an expandable liquid bag in a forefoot portion ofthe expandable shell (6); an expandable liquid bag in an upper midfootportion of the expandable shell (6).
 35. Expandable last (2) accordingto any of claims 31 to 34, wherein the at least one expandable liquidbag (26) is at least partly filled with an open-cell foam, in particularwith an open-cell polyurethane foam, and/or with a spacer fabric (34).36. Expandable last (2) according to any of claims 21 to 35, furthercomprising a lid (10), to which the core support element (4) and theexpandable shell (6) are mounted.
 37. Expandable last (2) according toclaim 36, wherein the liquid port (16) is arranged in the lid (10). 38.Expandable last (2) according to claim 36 or 37, wherein the lid (10)has an extension substantially corresponding to a transversecross-section of the collar of the footwear (110).
 39. Expandable last(2) according to any of claims 21 to 38, further comprising a heater,configured to heat the liquid in the liquid chamber (8) and/or to heatthe expandable shell (6).
 40. Expandable last (2) according to any ofclaims 21 to 39, configured for furnishing the footwear with awaterproof, breathable bootie, the waterproof, breathable bootie inparticular being provided, on its outside, with pressure sensitiveadhesive and/or heat-activated adhesive for attachment to the inside ofthe footwear.
 41. Expandable last (2) for furnishing footwear (110) withan insert (100), comprising: an expandable shell (6); a liquid chamber(8) within the expandable shell (6); and a liquid port (16), providingliquid communication between the liquid chamber (8) and an externalliquid source (120); wherein the expandable last (2) is insertable intothe footwear (110) through a collar of the footwear (110) and wherein,when receiving liquid in the liquid chamber (8) via the liquid port(16), the expandable shell (6) is configured to expand for pressing theinsert (100) towards an inside of the footwear (110); and wherein theexpandable shell (6) has, at least in one or more regions thereof,dimension-specific elastic properties.
 42. Expandable last (2) accordingto claim 41, wherein the expandable shell (6) is configured to expandmore easily in a longitudinal dimension (72) than in a circumferentialdimension (74) in at least one of a midfoot portion (70) and a forefootportion.
 43. Expandable last (2) according to claim 41 or 42, whereinthe expandable last (2) is free of a form-stable core support elementand/or free of an expansion assembly, arranged within the expandableshell.
 44. Expandable last (2) for furnishing footwear (110) with aninsert (100), comprising: a rigid last portion (80, 82); an expandableshell (6), arranged adjacent to the rigid last portion (80, 82); aliquid chamber (8) within the expandable shell (6); and a liquid port(16), providing liquid communication between the liquid chamber (8) andan external liquid source (120); wherein the expandable last (2) isinsertable into the footwear (110) through a collar of the footwear(110) and wherein, when receiving liquid in the liquid chamber (8) viathe liquid port (16), the expandable shell (6) is configured to expandfor pressing the insert (100) towards an inside of the footwear (110).45. Expandable last (2) according to claim 44, wherein the rigid lastportion (80, 82) is made from metal, such as aluminum.
 46. Expandablelast (2) according to claim 44 or 45, wherein the rigid last portion(80, 82) is heatable.
 47. Expandable last (2) according to any of claims44 to 46, comprising a rigid forefoot and instep last portion (80) and arigid heel last portion (82), wherein the expandable shell (6) isarranged between the rigid forefoot and instep last portion (80) and therigid heel last portion (82).
 48. Expandable last (2) according to claim47, wherein the rigid forefoot and instep last portion (80) and therigid heel last portion (82) are movable with respect to each other andwherein the expandable last comprises an actuator (84) for controlling aspacing between the rigid forefoot and instep last portion (80) and therigid heel last portion (82), with the actuator (84) in particular beinga pneumatic or hydraulic or electric actuator.
 49. Expandable last (2)according to any of claims 44 to 48, further comprising at least oneexpandable liquid bag (26), arranged on an outside of the rigid lastportion (80, 82).
 50. Expandable last (2) according to claim 49, whereinthe at least one expandable liquid bag (26) comprises at least oneexpandable liquid bag in a toe region and/or in a heel region of theexpandable last (2), in particular an expandable liquid bag in a toeregion of the rigid forefoot and instep last portion (80). 51.Expandable last (2) for furnishing footwear (110) with an insert (100),comprising: an expandable shell (6); a granulate chamber (61) within theexpandable shell (6); and a granulate port (62), providing a granulatechannel between the granulate chamber (61) and an external granulatesource (64), in particular between the granulate chamber (61) and anexternal heated granulate source (64); wherein the expandable last (2)is insertable into the footwear (110) through a collar of the footwear(110) and wherein, when receiving granulate (63) in the granulatechamber (61) via the granulate port (62), the expandable shell (6) isconfigured to expand for pressing the insert (100) towards an inside ofthe footwear (110).
 52. Method for furnishing footwear (110) with aninsert (100) using an expandable last (2) according to any of thepreceding claims.
 53. Method according to claim 52, wherein the insert(100) is a waterproof, breathable bootie.
 54. Method for furnishingfootwear (110) with an insert (100), the method comprising: inserting anexpandable last (2) into the footwear (110) through a collar of thefootwear (110), the expandable last (2) having an expandable shell (6)and a liquid chamber (8) within the expandable shell; and pressing theinsert (100) towards an inside of the footwear (110) by expanding theexpandable shell (6) via liquid in the liquid chamber (8).
 55. Methodaccording to claim 54, wherein said expanding of the expandable shell(6) via liquid in the liquid chamber (8) comprises introducing liquidinto the liquid chamber (8).
 56. Method according to claim 54 or 55,wherein said expanding of the expandable shell (6) via liquid in theliquid chamber (8) comprises heating the liquid in the liquid chamber(8).
 57. Method according to any of claims 54 to 56, wherein the insert(100) is a waterproof, breathable bootie.